Switch from NULL to nullptr.

65 files changed, 169 insertions, 169 deletions

diff --git a/src/modules/extra/m_argon2.cpp b/src/modules/extra/m_argon2.cpp
index 58e11eef0..d15fcf9bd 100644
--- a/src/modules/extra/m_argon2.cpp
+++ b/src/modules/extra/m_argon2.cpp
@@ -186,7 +186,7 @@ public:
 
 	void ReadConfig(ConfigStatus& status) override
 	{
-		ProviderConfig defaultConfig("argon2", NULL);
+		ProviderConfig defaultConfig("argon2", nullptr);
 		argon2i.config = ProviderConfig("argon2i", &defaultConfig);
 		argon2d.config = ProviderConfig("argon2d", &defaultConfig);
 		argon2id.config = ProviderConfig("argon2id", &defaultConfig);
diff --git a/src/modules/extra/m_geo_maxmind.cpp b/src/modules/extra/m_geo_maxmind.cpp
index 6a69d4a0e..80535c8d3 100644
--- a/src/modules/extra/m_geo_maxmind.cpp
+++ b/src/modules/extra/m_geo_maxmind.cpp
@@ -98,7 +98,7 @@ public:
 		// Attempt to locate this user.
 		location = GetLocation(user->client_sa);
 		if (!location)
-			return NULL;
+			return nullptr;
 
 		// We found the user. Cache their location for future use.
 		ext.Set(user, location);
@@ -109,19 +109,19 @@ public:
 	{
 		// Skip trying to look up a UNIX socket.
 		if (sa.family() != AF_INET && sa.family() != AF_INET6)
-			return NULL;
+			return nullptr;
 
 		// Attempt to look up the socket address.
 		int result;
 		MMDB_lookup_result_s lookup = MMDB_lookup_sockaddr(&mmdb, &sa.sa, &result);
 		if (result != MMDB_SUCCESS || !lookup.found_entry)
-			return NULL;
+			return nullptr;
 
 		// Attempt to retrieve the country code.
 		MMDB_entry_data_s country_code;
-		result = MMDB_get_value(&lookup.entry, &country_code, "country", "iso_code", NULL);
+		result = MMDB_get_value(&lookup.entry, &country_code, "country", "iso_code", nullptr);
 		if (result != MMDB_SUCCESS || !country_code.has_data || country_code.type != MMDB_DATA_TYPE_UTF8_STRING || country_code.data_size != 2)
-			return NULL;
+			return nullptr;
 
 		// If the country has been seen before then use our cached Location object.
 		const std::string code(country_code.utf8_string, country_code.data_size);
@@ -131,9 +131,9 @@ public:
 
 		// Attempt to retrieve the country name.
 		MMDB_entry_data_s country_name;
-		result = MMDB_get_value(&lookup.entry, &country_name, "country", "names", "en", NULL);
+		result = MMDB_get_value(&lookup.entry, &country_name, "country", "names", "en", nullptr);
 		if (result != MMDB_SUCCESS || !country_name.has_data || country_name.type != MMDB_DATA_TYPE_UTF8_STRING)
-			return NULL;
+			return nullptr;
 
 		// Create a Location object and cache it.
 		const std::string cname(country_name.utf8_string, country_name.data_size);
diff --git a/src/modules/extra/m_ldap.cpp b/src/modules/extra/m_ldap.cpp
index c1dfa40d9..ce327c3e8 100644
--- a/src/modules/extra/m_ldap.cpp
+++ b/src/modules/extra/m_ldap.cpp
@@ -79,7 +79,7 @@ public:
 	virtual ~LDAPRequest()
 	{
 		delete result;
-		if (message != NULL)
+		if (message != nullptr)
 			ldap_msgfree(message);
 	}
 
@@ -244,14 +244,14 @@ public:
 
 	static void FreeMods(LDAPMod** mods)
 	{
-		for (unsigned int i = 0; mods[i] != NULL; ++i)
+		for (unsigned int i = 0; mods[i] != nullptr; ++i)
 		{
 			LDAPMod* mod = mods[i];
-			if (mod->mod_type != NULL)
+			if (mod->mod_type != nullptr)
 				free(mod->mod_type);
-			if (mod->mod_values != NULL)
+			if (mod->mod_values != nullptr)
 			{
-				for (unsigned int j = 0; mod->mod_values[j] != NULL; ++j)
+				for (unsigned int j = 0; mod->mod_values[j] != nullptr; ++j)
 					free(mod->mod_values[j]);
 				delete[] mod->mod_values;
 			}
@@ -267,7 +267,7 @@ private:
 			throw LDAPException("Unable to connect to LDAP service " + this->name + ": reconnecting too fast");
 		last_connect = ServerInstance->Time();
 
-		ldap_unbind_ext(this->con, NULL, NULL);
+		ldap_unbind_ext(this->con, nullptr, nullptr);
 		Connect();
 	}
 
@@ -276,8 +276,8 @@ private:
 		int ret = ldap_set_option(this->con, option, value);
 		if (ret != LDAP_OPT_SUCCESS)
 		{
-			ldap_unbind_ext(this->con, NULL, NULL);
-			this->con = NULL;
+			ldap_unbind_ext(this->con, nullptr, nullptr);
+			this->con = nullptr;
 		}
 		return ret;
 	}
@@ -342,7 +342,7 @@ public:
 
 		this->UnlockQueue();
 
-		ldap_unbind_ext(this->con, NULL, NULL);
+		ldap_unbind_ext(this->con, nullptr, nullptr);
 	}
 
 	void Connect()
@@ -433,14 +433,14 @@ private:
 			LDAPAttributes attributes;
 
 			char* dn = ldap_get_dn(this->con, cur);
-			if (dn != NULL)
+			if (dn != nullptr)
 			{
 				attributes["dn"].push_back(dn);
 				ldap_memfree(dn);
-				dn = NULL;
+				dn = nullptr;
 			}
 
-			BerElement* ber = NULL;
+			BerElement* ber = nullptr;
 
 			for (char* attr = ldap_first_attribute(this->con, cur, &ber); attr; attr = ldap_next_attribute(this->con, cur, ber))
 			{
@@ -455,7 +455,7 @@ private:
 				ldap_value_free_len(vals);
 				ldap_memfree(attr);
 			}
-			if (ber != NULL)
+			if (ber != nullptr)
 				ber_free(ber, 0);
 
 			ldap_result->messages.push_back(attributes);
@@ -656,7 +656,7 @@ int LDAPBind::run()
 	cred.bv_val = strdup(pass.c_str());
 	cred.bv_len = pass.length();
 
-	int i = ldap_sasl_bind_s(service->GetConnection(), who.c_str(), LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
+	int i = ldap_sasl_bind_s(service->GetConnection(), who.c_str(), LDAP_SASL_SIMPLE, &cred, nullptr, nullptr, nullptr);
 
 	free(cred.bv_val);
 
@@ -670,7 +670,7 @@ std::string LDAPBind::info()
 
 int LDAPSearch::run()
 {
-	return ldap_search_ext_s(service->GetConnection(), base.c_str(), searchscope, filter.c_str(), NULL, 0, NULL, NULL, &tv, 0, &message);
+	return ldap_search_ext_s(service->GetConnection(), base.c_str(), searchscope, filter.c_str(), nullptr, 0, nullptr, nullptr, &tv, 0, &message);
 }
 
 std::string LDAPSearch::info()
@@ -681,7 +681,7 @@ std::string LDAPSearch::info()
 int LDAPAdd::run()
 {
 	LDAPMod** mods = LDAPService::BuildMods(attributes);
-	int i = ldap_add_ext_s(service->GetConnection(), dn.c_str(), mods, NULL, NULL);
+	int i = ldap_add_ext_s(service->GetConnection(), dn.c_str(), mods, nullptr, nullptr);
 	LDAPService::FreeMods(mods);
 	return i;
 }
@@ -693,7 +693,7 @@ std::string LDAPAdd::info()
 
 int LDAPDel::run()
 {
-	return ldap_delete_ext_s(service->GetConnection(), dn.c_str(), NULL, NULL);
+	return ldap_delete_ext_s(service->GetConnection(), dn.c_str(), nullptr, nullptr);
 }
 
 std::string LDAPDel::info()
@@ -704,7 +704,7 @@ std::string LDAPDel::info()
 int LDAPModify::run()
 {
 	LDAPMod** mods = LDAPService::BuildMods(attributes);
-	int i = ldap_modify_ext_s(service->GetConnection(), base.c_str(), mods, NULL, NULL);
+	int i = ldap_modify_ext_s(service->GetConnection(), base.c_str(), mods, nullptr, nullptr);
 	LDAPService::FreeMods(mods);
 	return i;
 }
@@ -720,7 +720,7 @@ int LDAPCompare::run()
 	cred.bv_val = strdup(val.c_str());
 	cred.bv_len = val.length();
 
-	int ret = ldap_compare_ext_s(service->GetConnection(), dn.c_str(), attr.c_str(), &cred, NULL, NULL);
+	int ret = ldap_compare_ext_s(service->GetConnection(), dn.c_str(), attr.c_str(), &cred, nullptr, nullptr);
 
 	free(cred.bv_val);
 
diff --git a/src/modules/extra/m_mysql.cpp b/src/modules/extra/m_mysql.cpp
index 9e1406578..ead27295e 100644
--- a/src/modules/extra/m_mysql.cpp
+++ b/src/modules/extra/m_mysql.cpp
@@ -327,7 +327,7 @@ public:
 		const std::string pass = config->getString("pass");
 		const std::string dbname = config->getString("name");
 		unsigned int port = static_cast<unsigned int>(config->getUInt("port", 3306, 1, 65535));
-		if (!mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, CLIENT_IGNORE_SIGPIPE))
+		if (!mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, nullptr, CLIENT_IGNORE_SIGPIPE))
 		{
 			ServerInstance->Logs.Normal(MODNAME, "Unable to connect to the %s MySQL server: %s",
 				GetId().c_str(), mysql_error(connection));
@@ -435,7 +435,7 @@ public:
 
 void ModuleSQL::init()
 {
-	if (mysql_library_init(0, NULL, NULL))
+	if (mysql_library_init(0, nullptr, nullptr))
 		throw ModuleException(this, "Unable to initialise the MySQL library!");
 
 	Dispatcher = new DispatcherThread(this);
diff --git a/src/modules/extra/m_pgsql.cpp b/src/modules/extra/m_pgsql.cpp
index 30d2690a6..f2e23d2e0 100644
--- a/src/modules/extra/m_pgsql.cpp
+++ b/src/modules/extra/m_pgsql.cpp
@@ -198,7 +198,7 @@ public:
 	SQLConn(Module* Creator, std::shared_ptr<ConfigTag> tag)
 		: SQL::Provider(Creator, tag->getString("id"))
 		, conf(tag)
-		, qinprog(NULL, "")
+		, qinprog(nullptr, "")
 	{
 		if (!DoConnect())
 			DelayReconnect();
@@ -384,7 +384,7 @@ restart:
 				}
 
 				delete qinprog.c;
-				qinprog = QueueItem(NULL, "");
+				qinprog = QueueItem(nullptr, "");
 				goto restart;
 			}
 			else
@@ -520,7 +520,7 @@ restart:
 		if(sql)
 		{
 			PQfinish(sql);
-			sql = NULL;
+			sql = nullptr;
 		}
 	}
 };
@@ -599,7 +599,7 @@ public:
 			{
 				conn->qinprog.c->OnError(err);
 				delete conn->qinprog.c;
-				conn->qinprog.c = NULL;
+				conn->qinprog.c = nullptr;
 			}
 			std::deque<QueueItem>::iterator j = conn->queue.begin();
 			while (j != conn->queue.end())
@@ -620,7 +620,7 @@ public:
 
 bool ReconnectTimer::Tick()
 {
-	mod->retimer = NULL;
+	mod->retimer = nullptr;
 	mod->ReadConf();
 	delete this;
 	return false;
diff --git a/src/modules/extra/m_regex_posix.cpp b/src/modules/extra/m_regex_posix.cpp
index 377939867..819046e2b 100644
--- a/src/modules/extra/m_regex_posix.cpp
+++ b/src/modules/extra/m_regex_posix.cpp
@@ -47,7 +47,7 @@ public:
 			return;
 
 		// Retrieve the size of the error message and allocate a buffer.
-		size_t errorsize = regerror(error, &regex, NULL, 0);
+		size_t errorsize = regerror(error, &regex, nullptr, 0);
 		std::vector<char> errormsg(errorsize);
 
 		// Retrieve the error message and free the buffer.
@@ -64,7 +64,7 @@ public:
 
 	bool IsMatch(const std::string& text) override
 	{
-		return !regexec(&regex, text.c_str(), 0, NULL, 0);
+		return !regexec(&regex, text.c_str(), 0, nullptr, 0);
 	}
 
 	std::optional<Regex::MatchCollection> Matches(const std::string& text) override
diff --git a/src/modules/extra/m_sqlite3.cpp b/src/modules/extra/m_sqlite3.cpp
index a388d3797..797f54a51 100644
--- a/src/modules/extra/m_sqlite3.cpp
+++ b/src/modules/extra/m_sqlite3.cpp
@@ -106,11 +106,11 @@ public:
 		, config(tag)
 	{
 		std::string host = tag->getString("hostname");
-		if (sqlite3_open_v2(host.c_str(), &conn, SQLITE_OPEN_READWRITE, 0) != SQLITE_OK)
+		if (sqlite3_open_v2(host.c_str(), &conn, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK)
 		{
 			// Even in case of an error conn must be closed
 			sqlite3_close(conn);
-			conn = NULL;
+			conn = nullptr;
 			ServerInstance->Logs.Normal(MODNAME, "WARNING: Could not open DB with id: " + tag->getString("id"));
 		}
 	}
@@ -128,7 +128,7 @@ public:
 	{
 		SQLite3Result res;
 		sqlite3_stmt *stmt;
-		int err = sqlite3_prepare_v2(conn, q.c_str(), static_cast<int>(q.length()), &stmt, NULL);
+		int err = sqlite3_prepare_v2(conn, q.c_str(), static_cast<int>(q.length()), &stmt, nullptr);
 		if (err != SQLITE_OK)
 		{
 			SQL::Error error(SQL::QSEND_FAIL, sqlite3_errmsg(conn));
diff --git a/src/modules/extra/m_ssl_gnutls.cpp b/src/modules/extra/m_ssl_gnutls.cpp
index 11ec78db0..b21ce982f 100644
--- a/src/modules/extra/m_ssl_gnutls.cpp
+++ b/src/modules/extra/m_ssl_gnutls.cpp
@@ -129,7 +129,7 @@ namespace GnuTLS
 			gnutls_hash_hd_t is_digest;
 			if (gnutls_hash_init(&is_digest, hash) < 0)
 				throw Exception("Unknown hash type " + hashname);
-			gnutls_hash_deinit(is_digest, NULL);
+			gnutls_hash_deinit(is_digest, nullptr);
 		}
 
 		gnutls_digest_algorithm_t get() const { return hash; }
@@ -311,7 +311,7 @@ namespace GnuTLS
 				ret.append(token);
 
 				gnutls_priority_t test;
-				if (gnutls_priority_init(&test, ret.c_str(), NULL) < 0)
+				if (gnutls_priority_init(&test, ret.c_str(), nullptr) < 0)
 				{
 					// The new token broke the priority string, revert to the previously working one
 					ServerInstance->Logs.Debug(MODNAME, "Priority string token not recognized: \"%s\"", token.c_str());
@@ -441,7 +441,7 @@ namespace GnuTLS
 		{
 			// Copy data from GnuTLS buffers to recvq
 			gnutls_datum_t datum;
-			gnutls_packet_get(packet, &datum, NULL);
+			gnutls_packet_get(packet, &datum, nullptr);
 			recvq.append(reinterpret_cast<const char*>(datum.data), datum.size);
 
 			gnutls_packet_deinit(packet);
@@ -610,8 +610,8 @@ private:
 			gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 			gnutls_deinit(this->sess);
 		}
-		sess = NULL;
-		certificate = NULL;
+		sess = nullptr;
+		certificate = nullptr;
 		status = STATUS_NONE;
 	}
 
@@ -1116,7 +1116,7 @@ public:
 
 	void init() override
 	{
-		ServerInstance->Logs.Normal(MODNAME, "GnuTLS lib version %s module was compiled for " GNUTLS_VERSION, gnutls_check_version(NULL));
+		ServerInstance->Logs.Normal(MODNAME, "GnuTLS lib version %s module was compiled for " GNUTLS_VERSION, gnutls_check_version(nullptr));
 		ServerInstance->GenRandom = GnuTLS::GenRandom;
 	}
 
diff --git a/src/modules/extra/m_ssl_mbedtls.cpp b/src/modules/extra/m_ssl_mbedtls.cpp
index 67a5cac79..2b4b34bc5 100644
--- a/src/modules/extra/m_ssl_mbedtls.cpp
+++ b/src/modules/extra/m_ssl_mbedtls.cpp
@@ -106,7 +106,7 @@ namespace mbedTLS
 	public:
 		bool Seed(Entropy& entropy)
 		{
-			return (mbedtls_ctr_drbg_seed(get(), mbedtls_entropy_func, entropy.get(), NULL, 0) == 0);
+			return (mbedtls_ctr_drbg_seed(get(), mbedtls_entropy_func, entropy.get(), nullptr, 0) == 0);
 		}
 
 		void SetupConf(mbedtls_ssl_config* conf)
@@ -136,10 +136,10 @@ namespace mbedTLS
 		{
 #if MBEDTLS_VERSION_MAJOR >= 3
 			int ret = mbedtls_pk_parse_key(get(), reinterpret_cast<const unsigned char*>(keystr.c_str()),
-				keystr.size() + 1, NULL, 0, mbedtls_ctr_drbg_random, 0);
+				keystr.size() + 1, nullptr, 0, mbedtls_ctr_drbg_random, 0);
 #else
 			int ret = mbedtls_pk_parse_key(get(), reinterpret_cast<const unsigned char*>(keystr.c_str()),
-				keystr.size() + 1, NULL, 0);
+				keystr.size() + 1, nullptr, 0);
 #endif
 			ThrowOnError(ret, "Unable to import private key");
 		}
@@ -221,7 +221,7 @@ namespace mbedTLS
 			ThrowOnError(ret, "Unable to load certificates");
 		}
 
-		bool empty() const { return (get()->raw.p != NULL); }
+		bool empty() const { return (get()->raw.p != nullptr); }
 	};
 
 	class X509CRL final
@@ -295,7 +295,7 @@ namespace mbedTLS
 			mbedtls_ssl_config_init(&conf);
 #ifdef INSPIRCD_MBEDTLS_LIBRARY_DEBUG
 			mbedtls_debug_set_threshold(INT_MAX);
-			mbedtls_ssl_conf_dbg(&conf, DebugLogFunc, NULL);
+			mbedtls_ssl_conf_dbg(&conf, DebugLogFunc, nullptr);
 #endif
 
 			// TODO: check ret of mbedtls_ssl_config_defaults
@@ -555,7 +555,7 @@ private:
 
 		mbedtls_ssl_close_notify(&sess);
 		mbedtls_ssl_free(&sess);
-		certificate = NULL;
+		certificate = nullptr;
 		status = STATUS_NONE;
 	}
 
@@ -709,7 +709,7 @@ public:
 		else
 			GetProfile().SetupClientSession(&sess);
 
-		mbedtls_ssl_set_bio(&sess, reinterpret_cast<void*>(sock), Push, Pull, NULL);
+		mbedtls_ssl_set_bio(&sess, reinterpret_cast<void*>(sock), Push, Pull, nullptr);
 
 		sock->AddIOHook(this);
 		Handshake(sock);
diff --git a/src/modules/extra/m_ssl_openssl.cpp b/src/modules/extra/m_ssl_openssl.cpp
index 002411fa8..a7ad33aa4 100644
--- a/src/modules/extra/m_ssl_openssl.cpp
+++ b/src/modules/extra/m_ssl_openssl.cpp
@@ -64,7 +64,7 @@ static Module* thismod;
 
 char* get_error()
 {
-	return ERR_error_string(ERR_get_error(), NULL);
+	return ERR_error_string(ERR_get_error(), nullptr);
 }
 
 static int OnVerify(int preverify_ok, X509_STORE_CTX* ctx);
@@ -94,7 +94,7 @@ namespace OpenSSL
 			if (!dhpfile)
 				throw Exception("Couldn't open DH file " + filename);
 
-			dh = PEM_read_bio_DHparams(dhpfile, NULL, NULL, NULL);
+			dh = PEM_read_bio_DHparams(dhpfile, nullptr, nullptr, nullptr);
 			BIO_free(dhpfile);
 
 			if (!dh)
@@ -140,7 +140,7 @@ namespace OpenSSL
 			mode |= SSL_MODE_RELEASE_BUFFERS;
 #endif
 			SSL_CTX_set_mode(ctx, mode);
-			SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+			SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, nullptr);
 			SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
 			SSL_CTX_set_info_callback(ctx, StaticSSLInfoCallback);
 		}
@@ -200,7 +200,7 @@ namespace OpenSSL
 		bool SetCA(const std::string& filename)
 		{
 			ERR_clear_error();
-			return SSL_CTX_load_verify_locations(ctx, filename.c_str(), 0);
+			return SSL_CTX_load_verify_locations(ctx, filename.c_str(), nullptr);
 		}
 
 		void SetCRL(const std::string& crlfile, const std::string& crlpath, const std::string& crlmode)
@@ -227,11 +227,11 @@ namespace OpenSSL
 			}
 			ERR_clear_error();
 			if (!X509_STORE_load_locations(store,
-				crlfile.empty() ? NULL : crlfile.c_str(),
-				crlpath.empty() ? NULL : crlpath.c_str()))
+				crlfile.empty() ? nullptr : crlfile.c_str(),
+				crlpath.empty() ? nullptr : crlpath.c_str()))
 			{
 				unsigned long err = ERR_get_error();
-				throw ModuleException(thismod, "Unable to load CRL file '" + crlfile + "' or CRL path '" + crlpath + "': '" + (err ? ERR_error_string(err, NULL) : "unknown") + "'");
+				throw ModuleException(thismod, "Unable to load CRL file '" + crlfile + "' or CRL path '" + crlpath + "': '" + (err ? ERR_error_string(err, nullptr) : "unknown") + "'");
 			}
 
 			/* Set CRL mode */
@@ -562,8 +562,8 @@ private:
 			SSL_shutdown(sess);
 			SSL_free(sess);
 		}
-		sess = NULL;
-		certificate = NULL;
+		sess = nullptr;
+		certificate = nullptr;
 		status = STATUS_NONE;
 	}
 
@@ -978,7 +978,7 @@ public:
 		: Module(VF_VENDOR, "Allows TLS encrypted connections using the OpenSSL library.")
 	{
 		// Initialize OpenSSL
-		OPENSSL_init_ssl(0, NULL);
+		OPENSSL_init_ssl(0, nullptr);
 		biomethods = OpenSSL::BIOMethod::alloc();
 
 		thismod = this;
@@ -995,7 +995,7 @@ public:
 
 		// Register application specific data
 		char exdatastr[] = "inspircd";
-		exdataindex = SSL_get_ex_new_index(0, exdatastr, NULL, NULL, NULL);
+		exdataindex = SSL_get_ex_new_index(0, exdatastr, nullptr, nullptr, nullptr);
 		if (exdataindex < 0)
 			throw ModuleException(this, "Failed to register application specific data");
 	}
diff --git a/src/modules/extra/m_sslrehashsignal.cpp b/src/modules/extra/m_sslrehashsignal.cpp
index 41b90d6df..e8abe7a1d 100644
--- a/src/modules/extra/m_sslrehashsignal.cpp
+++ b/src/modules/extra/m_sslrehashsignal.cpp
@@ -57,7 +57,7 @@ public:
 		ServerInstance->Logs.Normal(MODNAME, feedbackmsg);
 
 		const std::string str = "tls";
-		FOREACH_MOD(OnModuleRehash, (NULL, str));
+		FOREACH_MOD(OnModuleRehash, (nullptr, str));
 		signaled = 0;
 	}
 };
diff --git a/src/modules/m_alias.cpp b/src/modules/m_alias.cpp
index 70b302f6e..621fa4f04 100644
--- a/src/modules/m_alias.cpp
+++ b/src/modules/m_alias.cpp
@@ -181,7 +181,7 @@ public:
 		{
 			if (alias.UserCommand)
 			{
-				if (DoAlias(user, NULL, alias, compare, original_line))
+				if (DoAlias(user, nullptr, alias, compare, original_line))
 				{
 					return MOD_RES_DENY;
 				}
diff --git a/src/modules/m_autoop.cpp b/src/modules/m_autoop.cpp
index c7bd7039c..dca983b3e 100644
--- a/src/modules/m_autoop.cpp
+++ b/src/modules/m_autoop.cpp
@@ -48,7 +48,7 @@ public:
 			return ServerInstance->Modes.FindPrefixMode(mid[0]);
 
 		ModeHandler* mh = ServerInstance->Modes.FindMode(mid, MODETYPE_CHANNEL);
-		return mh ? mh->IsPrefixMode() : NULL;
+		return mh ? mh->IsPrefixMode() : nullptr;
 	}
 
 	ModResult AccessCheck(User* source, Channel* channel, Modes::Change& change) override
@@ -117,7 +117,7 @@ public:
 						changelist.push_add(given, memb->user->nick);
 				}
 			}
-			ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, NULL, changelist);
+			ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, nullptr, changelist);
 		}
 	}
 
diff --git a/src/modules/m_banredirect.cpp b/src/modules/m_banredirect.cpp
index 1926bf464..02db49a89 100644
--- a/src/modules/m_banredirect.cpp
+++ b/src/modules/m_banredirect.cpp
@@ -282,7 +282,7 @@ public:
 				for (const auto& redirect : *redirects)
 					changelist.push_add(*banwatcher.banmode, redirect.banmask);
 
-				ServerInstance->Modes.Process(ServerInstance->FakeClient, chan, NULL, changelist, ModeParser::MODE_LOCALONLY);
+				ServerInstance->Modes.Process(ServerInstance->FakeClient, chan, nullptr, changelist, ModeParser::MODE_LOCALONLY);
 			}
 		}
 	}
diff --git a/src/modules/m_callerid.cpp b/src/modules/m_callerid.cpp
index 60cfba367..cb51f458d 100644
--- a/src/modules/m_callerid.cpp
+++ b/src/modules/m_callerid.cpp
@@ -102,7 +102,7 @@ struct CallerIDExtInfo final
 
 		void* old = GetRaw(container);
 		if (old)
-			this->Delete(NULL, old);
+			this->Delete(nullptr, old);
 		callerid_data* dat = new callerid_data;
 		SetRaw(container, dat);
 
@@ -164,7 +164,7 @@ class CommandAccept final
 	 */
 	typedef std::pair<User*, bool> ACCEPTAction;
 
-	static ACCEPTAction GetTargetAndAction(std::string& tok, User* cmdfrom = NULL)
+	static ACCEPTAction GetTargetAndAction(std::string& tok, User* cmdfrom = nullptr)
 	{
 		bool remove = (tok[0] == '-');
 		if ((remove) || (tok[0] == '+'))
@@ -177,7 +177,7 @@ class CommandAccept final
 			target = ServerInstance->Users.FindNick(tok);
 
 		if ((!target) || (target->registered != REG_ALL) || (target->quitting))
-			target = NULL;
+			target = nullptr;
 
 		return std::make_pair(target, !remove);
 	}
diff --git a/src/modules/m_cap.cpp b/src/modules/m_cap.cpp
index 06522b315..b4ba0d7ce 100644
--- a/src/modules/m_cap.cpp
+++ b/src/modules/m_cap.cpp
@@ -199,7 +199,7 @@ public:
 		CapMap::const_iterator it = caps.find(capname);
 		if (it != caps.end())
 			return it->second;
-		return NULL;
+		return nullptr;
 	}
 
 	void NotifyValueChange(Capability* cap) override
diff --git a/src/modules/m_chanfilter.cpp b/src/modules/m_chanfilter.cpp
index 36e0ade78..fe4176766 100644
--- a/src/modules/m_chanfilter.cpp
+++ b/src/modules/m_chanfilter.cpp
@@ -73,17 +73,17 @@ class ModuleChanFilter final
 	const ChanFilter::ListItem* Match(User* user, Channel* chan, const std::string& text)
 	{
 		if (!IS_LOCAL(user))
-			return NULL; // We don't handle remote users.
+			return nullptr; // We don't handle remote users.
 
 		if (user->HasPrivPermission("channels/ignore-chanfilter"))
-			return NULL; // The source is an exempt server operator.
+			return nullptr; // The source is an exempt server operator.
 
 		if (CheckExemption::Call(exemptionprov, user, chan, "filter") == MOD_RES_ALLOW)
-			return NULL; // The source matches an exemptchanops entry.
+			return nullptr; // The source matches an exemptchanops entry.
 
 		ListModeBase::ModeList* list = cf.GetList(chan);
 		if (!list)
-			return NULL;
+			return nullptr;
 
 		for (const auto& entry : *list)
 		{
@@ -91,7 +91,7 @@ class ModuleChanFilter final
 				return &entry;
 		}
 
-		return NULL;
+		return nullptr;
 	}
 
 public:
diff --git a/src/modules/m_channames.cpp b/src/modules/m_channames.cpp
index 931af03b9..7e88ee38a 100644
--- a/src/modules/m_channames.cpp
+++ b/src/modules/m_channames.cpp
@@ -79,7 +79,7 @@ public:
 			{
 				removepermchan.clear();
 				removepermchan.push_remove(*permchannelmode);
-				ServerInstance->Modes.Process(ServerInstance->FakeClient, c, NULL, removepermchan);
+				ServerInstance->Modes.Process(ServerInstance->FakeClient, c, nullptr, removepermchan);
 			}
 
 			Channel::MemberMap& users = c->userlist;
diff --git a/src/modules/m_clearchan.cpp b/src/modules/m_clearchan.cpp
index d3a646a3c..0718d8f0d 100644
--- a/src/modules/m_clearchan.cpp
+++ b/src/modules/m_clearchan.cpp
@@ -55,7 +55,7 @@ public:
 			std::transform(method.begin(), method.end(), method.begin(), ::toupper);
 		}
 
-		XLineFactory* xlf = NULL;
+		XLineFactory* xlf = nullptr;
 		bool kick = (method == "KICK");
 		if ((!kick) && (method != "KILL"))
 		{
diff --git a/src/modules/m_cloaking.cpp b/src/modules/m_cloaking.cpp
index 5271d5305..db7bd2e29 100644
--- a/src/modules/m_cloaking.cpp
+++ b/src/modules/m_cloaking.cpp
@@ -411,7 +411,7 @@ public:
 
 			Modes::ChangeList modechangelist;
 			modechangelist.push_remove(&cu);
-			ClientProtocol::Events::Mode modeevent(ServerInstance->FakeClient, NULL, u, modechangelist);
+			ClientProtocol::Events::Mode modeevent(ServerInstance->FakeClient, nullptr, u, modechangelist);
 			luser->Send(modeevent);
 		}
 		cu.active = false;
diff --git a/src/modules/m_connectban.cpp b/src/modules/m_connectban.cpp
index e074c9cc7..645345a82 100644
--- a/src/modules/m_connectban.cpp
+++ b/src/modules/m_connectban.cpp
@@ -148,7 +148,7 @@ public:
 			{
 				// Create Z-line for set duration.
 				ZLine* zl = new ZLine(ServerInstance->Time(), banduration, MODNAME "@" + ServerInstance->Config->ServerName, banmessage, mask.str());
-				if (!ServerInstance->XLines->AddLine(zl, NULL))
+				if (!ServerInstance->XLines->AddLine(zl, nullptr))
 				{
 					delete zl;
 					return;
diff --git a/src/modules/m_denychans.cpp b/src/modules/m_denychans.cpp
index 52da3b51f..a1babeccb 100644
--- a/src/modules/m_denychans.cpp
+++ b/src/modules/m_denychans.cpp
@@ -168,7 +168,7 @@ public:
 
 			// If there is no redirect chan, the user has enabled the antiredirect mode, or
 			// the target channel redirects elsewhere we just tell the user and deny the join.
-			Channel* target = NULL;
+			Channel* target = nullptr;
 			if (badchan.redirect.empty() || user->IsModeSet(antiredirectmode)
 				|| ((target = ServerInstance->Channels.Find(badchan.redirect)) && target->IsModeSet(redirectmode)))
 			{
diff --git a/src/modules/m_exemptchanops.cpp b/src/modules/m_exemptchanops.cpp
index eaa768308..7ea17e4f1 100644
--- a/src/modules/m_exemptchanops.cpp
+++ b/src/modules/m_exemptchanops.cpp
@@ -48,7 +48,7 @@ public:
 			return ServerInstance->Modes.FindPrefixMode(pmode[0]);
 
 		ModeHandler* mh = ServerInstance->Modes.FindMode(pmode, MODETYPE_CHANNEL);
-		return mh ? mh->IsPrefixMode() : NULL;
+		return mh ? mh->IsPrefixMode() : nullptr;
 	}
 
 	static bool ParseEntry(const std::string& entry, std::string& restriction, std::string& prefix)
diff --git a/src/modules/m_filter.cpp b/src/modules/m_filter.cpp
index 544ef99d8..51c13c07a 100644
--- a/src/modules/m_filter.cpp
+++ b/src/modules/m_filter.cpp
@@ -470,7 +470,7 @@ ModResult ModuleFilter::OnUserPreMessage(User* user, const MessageTarget& msgtar
 				user->nick.c_str(), sh->Displayable().c_str(), InspIRCd::DurationString(f->duration).c_str(),
 				InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 				msgtarget.GetName().c_str(), f->freeform.c_str(), f->reason.c_str()));
-			if (ServerInstance->XLines->AddLine(sh, NULL))
+			if (ServerInstance->XLines->AddLine(sh, nullptr))
 			{
 				ServerInstance->XLines->ApplyLines();
 			}
@@ -484,7 +484,7 @@ ModResult ModuleFilter::OnUserPreMessage(User* user, const MessageTarget& msgtar
 				user->nick.c_str(), gl->Displayable().c_str(), InspIRCd::DurationString(f->duration).c_str(),
 				InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 				msgtarget.GetName().c_str(), f->freeform.c_str(), f->reason.c_str()));
-			if (ServerInstance->XLines->AddLine(gl,NULL))
+			if (ServerInstance->XLines->AddLine(gl, nullptr))
 			{
 				ServerInstance->XLines->ApplyLines();
 			}
@@ -498,7 +498,7 @@ ModResult ModuleFilter::OnUserPreMessage(User* user, const MessageTarget& msgtar
 				user->nick.c_str(), zl->Displayable().c_str(), InspIRCd::DurationString(f->duration).c_str(),
 				InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 				msgtarget.GetName().c_str(), f->freeform.c_str(), f->reason.c_str()));
-			if (ServerInstance->XLines->AddLine(zl,NULL))
+			if (ServerInstance->XLines->AddLine(zl, nullptr))
 			{
 				ServerInstance->XLines->ApplyLines();
 			}
@@ -577,7 +577,7 @@ ModResult ModuleFilter::OnPreCommand(std::string& command, CommandBase::Params&
 					InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 					command.c_str(), f->freeform.c_str(), f->reason.c_str()));
 
-				if (ServerInstance->XLines->AddLine(gl,NULL))
+				if (ServerInstance->XLines->AddLine(gl, nullptr))
 				{
 					ServerInstance->XLines->ApplyLines();
 				}
@@ -593,7 +593,7 @@ ModResult ModuleFilter::OnPreCommand(std::string& command, CommandBase::Params&
 					InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 					command.c_str(), f->freeform.c_str(), f->reason.c_str()));
 
-				if (ServerInstance->XLines->AddLine(zl,NULL))
+				if (ServerInstance->XLines->AddLine(zl, nullptr))
 				{
 					ServerInstance->XLines->ApplyLines();
 				}
@@ -610,7 +610,7 @@ ModResult ModuleFilter::OnPreCommand(std::string& command, CommandBase::Params&
 					InspIRCd::TimeString(ServerInstance->Time() + f->duration).c_str(),
 					command.c_str(), f->freeform.c_str(), f->reason.c_str()));
 
-				if (ServerInstance->XLines->AddLine(sh, NULL))
+				if (ServerInstance->XLines->AddLine(sh, nullptr))
 				{
 					ServerInstance->XLines->ApplyLines();
 				}
@@ -649,7 +649,7 @@ void ModuleFilter::ReadConfig(ConfigStatus& status)
 		filterconf = ServerInstance->Config->Paths.PrependConfig(filterconf);
 	SetInterval(tag->getDuration("saveperiod", 5));
 
-	factory = RegexEngine ? (RegexEngine.operator->()) : NULL;
+	factory = RegexEngine ? (RegexEngine.operator->()) : nullptr;
 
 	RegexEngine.SetEngine(newrxengine);
 	if (!RegexEngine)
@@ -776,7 +776,7 @@ const FilterResult* ModuleFilter::FilterMatch(User* user, const std::string &tex
 		if (filter.regex->IsMatch(filter.flag_strip_color ? stripped_text : text))
 			return &filter;
 	}
-	return NULL;
+	return nullptr;
 }
 
 bool ModuleFilter::DeleteFilter(const std::string& freeform, std::string& reason)
diff --git a/src/modules/m_gateway.cpp b/src/modules/m_gateway.cpp
index 15e827507..448caefc1 100644
--- a/src/modules/m_gateway.cpp
+++ b/src/modules/m_gateway.cpp
@@ -170,7 +170,7 @@ public:
 
 	static bool ParseIP(const std::string& in, irc::sockets::sockaddrs& out)
 	{
-		const char* ident = NULL;
+		const char* ident = nullptr;
 		if (in.length() == 8)
 		{
 			// The ident is an IPv4 address encoded in hexadecimal with two characters
@@ -195,7 +195,7 @@ public:
 		// Try to convert the IP address to a string. If this fails then the user
 		// does not have an IPv4 address in their ident.
 		errno = 0;
-		unsigned long address = strtoul(ident, NULL, 16);
+		unsigned long address = strtoul(ident, nullptr, 16);
 		if (errno)
 			return false;
 
diff --git a/src/modules/m_geoban.cpp b/src/modules/m_geoban.cpp
index ecd8fe8e0..caaf038f6 100644
--- a/src/modules/m_geoban.cpp
+++ b/src/modules/m_geoban.cpp
@@ -39,7 +39,7 @@ public:
 
 	bool IsMatch(User* user, Channel* channel, const std::string& text) override
 	{
-		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : NULL;
+		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : nullptr;
 		const std::string code = location ? location->GetCode() : "XX";
 
 		// Does this user match against the ban?
@@ -71,7 +71,7 @@ public:
 		if (!request.flags['G'])
 			return MOD_RES_PASSTHRU;
 
-		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : NULL;
+		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : nullptr;
 		const std::string code = location ? location->GetCode() : "XX";
 		return InspIRCd::Match(code, request.matchtext, ascii_case_insensitive_map) ? MOD_RES_ALLOW : MOD_RES_DENY;
 	}
@@ -81,7 +81,7 @@ public:
 		if (whois.GetTarget()->server->IsService())
 			return;
 
-		Geolocation::Location* location = geoapi ? geoapi->GetLocation(whois.GetTarget()) : NULL;
+		Geolocation::Location* location = geoapi ? geoapi->GetLocation(whois.GetTarget()) : nullptr;
 		if (location)
 			whois.SendLine(RPL_WHOISCOUNTRY, location->GetCode(), "is connecting from " + location->GetName());
 		else
diff --git a/src/modules/m_geoclass.cpp b/src/modules/m_geoclass.cpp
index 4a0e53830..f381c57c4 100644
--- a/src/modules/m_geoclass.cpp
+++ b/src/modules/m_geoclass.cpp
@@ -44,7 +44,7 @@ public:
 
 		// If we can't find the location of this user then we can't assign
 		// them to a location-specific connect class.
-		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : NULL;
+		Geolocation::Location* location = geoapi ? geoapi->GetLocation(user) : nullptr;
 		const std::string code = location ? location->GetCode() : "XX";
 
 		irc::spacesepstream codes(country);
diff --git a/src/modules/m_hidemode.cpp b/src/modules/m_hidemode.cpp
index dcb1d4afd..8d6127d35 100644
--- a/src/modules/m_hidemode.cpp
+++ b/src/modules/m_hidemode.cpp
@@ -85,7 +85,7 @@ class ModeHook final
 
 	Modes::ChangeList* FilterModeChangeList(const ClientProtocol::Events::Mode& mode, ModeHandler::Rank rank)
 	{
-		Modes::ChangeList* modechangelist = NULL;
+		Modes::ChangeList* modechangelist = nullptr;
 		for (Modes::ChangeList::List::const_iterator i = mode.GetChangeList().getlist().begin(); i != mode.GetChangeList().getlist().end(); ++i)
 		{
 			const Modes::Change& curr = *i;
@@ -156,14 +156,14 @@ class ModeHook final
 			if (filteredchangelist->empty())
 			{
 				// This rank cannot see any mode changes in the original change list
-				finalmsgplist = NULL;
+				finalmsgplist = nullptr;
 			}
 			else
 			{
 				// This rank can see some of the mode changes in the filtered mode change list.
 				// Create and store a new protocol message from it.
 				filteredmsgplists.emplace_back();
-				ClientProtocol::Events::Mode::BuildMessages(mode.GetMessages().front().GetSourceUser(), chan, NULL, *filteredchangelist, filteredmodelist, filteredmsgplists.back());
+				ClientProtocol::Events::Mode::BuildMessages(mode.GetMessages().front().GetSourceUser(), chan, nullptr, *filteredchangelist, filteredmodelist, filteredmsgplists.back());
 				finalmsgplist = &filteredmsgplists.back();
 			}
 		}
diff --git a/src/modules/m_httpd.cpp b/src/modules/m_httpd.cpp
index 5b34a0ada..d0a6ae46f 100644
--- a/src/modules/m_httpd.cpp
+++ b/src/modules/m_httpd.cpp
@@ -250,7 +250,7 @@ public:
 		Close();
 	}
 
-	void SendHTTPError(unsigned int response, const char* errstr = NULL)
+	void SendHTTPError(unsigned int response, const char* errstr = nullptr)
 	{
 		if (!errstr)
 			errstr = http_status_str((http_status)response);
diff --git a/src/modules/m_ircv3_batch.cpp b/src/modules/m_ircv3_batch.cpp
index 7d81c60a5..065a543a4 100644
--- a/src/modules/m_ircv3_batch.cpp
+++ b/src/modules/m_ircv3_batch.cpp
@@ -163,7 +163,7 @@ public:
 			return;
 
 		// Mark batch as stopped
-		batch.manager = NULL;
+		batch.manager = nullptr;
 
 		BatchInfo& batchinfo = *batch.batchinfo;
 		// Send end batch message to all users who got the batch start message and unset bit so it can be reused
@@ -176,7 +176,7 @@ public:
 		// erase() not swaperase because the reftag generation logic depends on the order of the elements
 		stdalgo::erase(active_batches, &batch);
 		delete batch.batchinfo;
-		batch.batchinfo = NULL;
+		batch.batchinfo = nullptr;
 	}
 };
 
diff --git a/src/modules/m_ircv3_capnotify.cpp b/src/modules/m_ircv3_capnotify.cpp
index 4e2cf1863..9a06189fa 100644
--- a/src/modules/m_ircv3_capnotify.cpp
+++ b/src/modules/m_ircv3_capnotify.cpp
@@ -164,7 +164,7 @@ public:
 			return;
 		reloadedmod = mod->ModuleSourceFile;
 		// Request callback when reload is complete
-		cd.add(this, NULL);
+		cd.add(this, nullptr);
 	}
 
 	void OnReloadModuleRestore(Module* mod, void* data) override
@@ -178,7 +178,7 @@ public:
 			for (const auto& capname : reloadedcaps)
 			{
 				if (!capmanager->Find(capname))
-					Send(capname, NULL, false);
+					Send(capname, nullptr, false);
 			}
 		}
 		reloadedmod.clear();
diff --git a/src/modules/m_ircv3_ctctags.cpp b/src/modules/m_ircv3_ctctags.cpp
index 89efea12d..96295ed6a 100644
--- a/src/modules/m_ircv3_ctctags.cpp
+++ b/src/modules/m_ircv3_ctctags.cpp
@@ -163,7 +163,7 @@ private:
 				// The target is a user on a specific server (e.g. jto@tolsun.oulu.fi).
 				target = ServerInstance->Users.FindNick(parameters[0].substr(0, targetserver - parameters[0].c_str()));
 				if (target && strcasecmp(target->server->GetPublicName().c_str(), targetserver + 1))
-					target = NULL;
+					target = nullptr;
 			}
 			else
 			{
@@ -240,7 +240,7 @@ public:
 
 		// If the message begins with one or more status characters then look them up.
 		const char* target = parameters[0].c_str();
-		PrefixMode* targetpfx = NULL;
+		PrefixMode* targetpfx = nullptr;
 		for (PrefixMode* pfx; (pfx = ServerInstance->Modes.FindPrefix(target[0])); ++target)
 		{
 			// We want the lowest ranked prefix specified.
diff --git a/src/modules/m_ircv3_labeledresponse.cpp b/src/modules/m_ircv3_labeledresponse.cpp
index d4cbbbffe..c90154371 100644
--- a/src/modules/m_ircv3_labeledresponse.cpp
+++ b/src/modules/m_ircv3_labeledresponse.cpp
@@ -171,7 +171,7 @@ public:
 			}
 		}
 
-		tag.labeluser = NULL;
+		tag.labeluser = nullptr;
 		msgcount = 0;
 	}
 
diff --git a/src/modules/m_monitor.cpp b/src/modules/m_monitor.cpp
index d52033dd0..def2c6f5e 100644
--- a/src/modules/m_monitor.cpp
+++ b/src/modules/m_monitor.cpp
@@ -178,7 +178,7 @@ public:
 		Entry* entry = Find(nick);
 		if (entry)
 			return &entry->watchers;
-		return NULL;
+		return nullptr;
 	}
 
 	static User* FindNick(const std::string& nick)
@@ -186,7 +186,7 @@ public:
 		User* user = ServerInstance->Users.FindNick(nick);
 		if ((user) && (user->registered == REG_ALL))
 			return user;
-		return NULL;
+		return nullptr;
 	}
 
 private:
@@ -197,7 +197,7 @@ private:
 		NickHash::iterator it = nicks.find(nick);
 		if (it != nicks.end())
 			return &it->second;
-		return NULL;
+		return nullptr;
 	}
 
 	Entry* AddWatcher(const std::string& nick, LocalUser* user)
@@ -235,7 +235,7 @@ private:
 	{
 		ExtData* extdata = ext.Get(user, create);
 		if (!extdata)
-			return NULL;
+			return nullptr;
 		return &extdata->list;
 	}
 
diff --git a/src/modules/m_namedmodes.cpp b/src/modules/m_namedmodes.cpp
index 99c911fdc..f28a57747 100644
--- a/src/modules/m_namedmodes.cpp
+++ b/src/modules/m_namedmodes.cpp
@@ -104,7 +104,7 @@ public:
 					modes.push(mh, plus);
 			}
 		}
-		ServerInstance->Modes.ProcessSingle(src, chan, NULL, modes, ModeParser::MODE_CHECKACCESS);
+		ServerInstance->Modes.ProcessSingle(src, chan, nullptr, modes, ModeParser::MODE_CHECKACCESS);
 		return CmdResult::SUCCESS;
 	}
 };
diff --git a/src/modules/m_ojoin.cpp b/src/modules/m_ojoin.cpp
index 7b28bff3f..12b0b306e 100644
--- a/src/modules/m_ojoin.cpp
+++ b/src/modules/m_ojoin.cpp
@@ -76,7 +76,7 @@ public:
 			changelist.push_add(npmh, user->nick);
 			if (op && opmode)
 				changelist.push_add(*opmode, user->nick);
-			ServerInstance->Modes.Process(ServerInstance->FakeClient, channel, NULL, changelist);
+			ServerInstance->Modes.Process(ServerInstance->FakeClient, channel, nullptr, changelist);
 		}
 		return CmdResult::SUCCESS;
 	}
diff --git a/src/modules/m_operprefix.cpp b/src/modules/m_operprefix.cpp
index bc8236798..405f0bce0 100644
--- a/src/modules/m_operprefix.cpp
+++ b/src/modules/m_operprefix.cpp
@@ -93,7 +93,7 @@ public:
 		// The user was force joined and OnUserPreJoin() did not run. Set the operprefix now.
 		Modes::ChangeList changelist;
 		changelist.push_add(&opm, memb->user->nick);
-		ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, NULL, changelist);
+		ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, nullptr, changelist);
 	}
 
 	void SetOperPrefix(User* user, bool add)
@@ -101,7 +101,7 @@ public:
 		Modes::ChangeList changelist;
 		changelist.push(&opm, add, user->nick);
 		for (const auto* memb : user->chans)
-			ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, NULL, changelist);
+			ServerInstance->Modes.Process(ServerInstance->FakeClient, memb->chan, nullptr, changelist);
 	}
 
 	void OnPostOper(User* user) override
diff --git a/src/modules/m_password_hash.cpp b/src/modules/m_password_hash.cpp
index d7f9002a1..517183e1a 100644
--- a/src/modules/m_password_hash.cpp
+++ b/src/modules/m_password_hash.cpp
@@ -57,7 +57,7 @@ public:
 
 			std::string salt = ServerInstance->GenRandomStr(hp->out_size, false);
 			std::string target = hp->hmac(salt, parameters[1]);
-			std::string str = Base64::Encode(salt) + "$" + Base64::Encode(target, NULL, 0);
+			std::string str = Base64::Encode(salt) + "$" + Base64::Encode(target, nullptr, 0);
 
 			user->WriteNotice(parameters[0] + " hashed password for " + parameters[1] + " is " + str);
 			return CmdResult::SUCCESS;
diff --git a/src/modules/m_rline.cpp b/src/modules/m_rline.cpp
index 0095d6696..daf59ff7e 100644
--- a/src/modules/m_rline.cpp
+++ b/src/modules/m_rline.cpp
@@ -69,7 +69,7 @@ public:
 		if (ZlineOnMatch)
 		{
 			ZLine* zl = new ZLine(ServerInstance->Time(), duration ? expiry - ServerInstance->Time() : 0, MODNAME "@" + ServerInstance->Config->ServerName, reason.c_str(), u->GetIPString());
-			if (ServerInstance->XLines->AddLine(zl, NULL))
+			if (ServerInstance->XLines->AddLine(zl, nullptr))
 			{
 				if (!duration)
 				{
@@ -157,7 +157,7 @@ public:
 				user->WriteNotice("*** Invalid duration for R-line.");
 				return CmdResult::FAILURE;
 			}
-			XLine *r = NULL;
+			XLine *r = nullptr;
 
 			try
 			{
@@ -273,7 +273,7 @@ public:
 		ZlineOnMatch = tag->getBool("zlineonmatch");
 		std::string newrxengine = tag->getString("engine");
 
-		factory = rxfactory ? (rxfactory.operator->()) : NULL;
+		factory = rxfactory ? (rxfactory.operator->()) : nullptr;
 
 		rxfactory.SetEngine(newrxengine);
 		if (!rxfactory)
diff --git a/src/modules/m_rmode.cpp b/src/modules/m_rmode.cpp
index b084eab54..78d9ff4e2 100644
--- a/src/modules/m_rmode.cpp
+++ b/src/modules/m_rmode.cpp
@@ -76,7 +76,7 @@ public:
 					changelist.push_remove(mh, u->nick);
 			}
 		}
-		else if ((lm = mh->IsListModeBase()) && ((ml = lm->GetList(chan)) != NULL))
+		else if ((lm = mh->IsListModeBase()) && ((ml = lm->GetList(chan)) != nullptr))
 		{
 			for (const auto& entry : *ml)
 			{
@@ -90,7 +90,7 @@ public:
 				changelist.push_remove(mh);
 		}
 
-		ServerInstance->Modes.Process(user, chan, NULL, changelist);
+		ServerInstance->Modes.Process(user, chan, nullptr, changelist);
 		return CmdResult::SUCCESS;
 	}
 };
diff --git a/src/modules/m_samode.cpp b/src/modules/m_samode.cpp
index 4172f9470..fd2ecb37f 100644
--- a/src/modules/m_samode.cpp
+++ b/src/modules/m_samode.cpp
@@ -64,7 +64,7 @@ public:
 
 		// XXX: Make ModeParser clear LastParse
 		Modes::ChangeList emptychangelist;
-		ServerInstance->Modes.ProcessSingle(ServerInstance->FakeClient, NULL, ServerInstance->FakeClient, emptychangelist);
+		ServerInstance->Modes.ProcessSingle(ServerInstance->FakeClient, nullptr, ServerInstance->FakeClient, emptychangelist);
 
 		logged = false;
 		this->active = true;
diff --git a/src/modules/m_satopic.cpp b/src/modules/m_satopic.cpp
index 233524c01..a52a784d3 100644
--- a/src/modules/m_satopic.cpp
+++ b/src/modules/m_satopic.cpp
@@ -53,7 +53,7 @@ public:
 				return CmdResult::SUCCESS;
 			}
 
-			target->SetTopic(user, newTopic, ServerInstance->Time(), NULL);
+			target->SetTopic(user, newTopic, ServerInstance->Time(), nullptr);
 			ServerInstance->SNO.WriteGlobalSno('a', user->nick + " used SATOPIC on " + target->name + ", new topic: " + newTopic);
 
 			return CmdResult::SUCCESS;
diff --git a/src/modules/m_spanningtree/addline.cpp b/src/modules/m_spanningtree/addline.cpp
index 40c8bb80f..d3f12850b 100644
--- a/src/modules/m_spanningtree/addline.cpp
+++ b/src/modules/m_spanningtree/addline.cpp
@@ -42,7 +42,7 @@ CmdResult CommandAddLine::Handle(User* usr, Params& params)
 		return CmdResult::FAILURE;
 	}
 
-	XLine* xl = NULL;
+	XLine* xl = nullptr;
 	try
 	{
 		xl = xlf->Generate(ServerInstance->Time(), ConvToNum<unsigned long>(params[4]), params[2], params[5], params[1]);
@@ -53,7 +53,7 @@ CmdResult CommandAddLine::Handle(User* usr, Params& params)
 		return CmdResult::FAILURE;
 	}
 	xl->SetCreateTime(ServerCommand::ExtractTS(params[3]));
-	if (ServerInstance->XLines->AddLine(xl, NULL))
+	if (ServerInstance->XLines->AddLine(xl, nullptr))
 	{
 		if (xl->duration)
 		{
diff --git a/src/modules/m_spanningtree/encap.cpp b/src/modules/m_spanningtree/encap.cpp
index 00cde72fa..4e4524789 100644
--- a/src/modules/m_spanningtree/encap.cpp
+++ b/src/modules/m_spanningtree/encap.cpp
@@ -43,7 +43,7 @@ CmdResult CommandEncap::Handle(User* user, Params& params)
 			return CmdResult::SUCCESS;
 		}
 
-		Command* cmd = NULL;
+		Command* cmd = nullptr;
 		ServerInstance->Parser.CallHandler(params[1], plist, user, &cmd);
 		// Discard return value, ENCAP shall succeed even if the command does not exist
 
diff --git a/src/modules/m_spanningtree/fjoin.cpp b/src/modules/m_spanningtree/fjoin.cpp
index e5470d9c2..46de08382 100644
--- a/src/modules/m_spanningtree/fjoin.cpp
+++ b/src/modules/m_spanningtree/fjoin.cpp
@@ -166,7 +166,7 @@ CmdResult CommandFJoin::Handle(User* srcuser, Params& params)
 	if (apply_other_sides_modes)
 	{
 		ServerInstance->Modes.ModeParamsToChangeList(srcuser, MODETYPE_CHANNEL, params, modechangelist, 2, params.size() - 1);
-		ServerInstance->Modes.Process(srcuser, chan, NULL, modechangelist, ModeParser::MODE_LOCALONLY | ModeParser::MODE_MERGE);
+		ServerInstance->Modes.Process(srcuser, chan, nullptr, modechangelist, ModeParser::MODE_LOCALONLY | ModeParser::MODE_MERGE);
 		// Reuse for prefix modes
 		modechangelist.clear();
 	}
@@ -178,7 +178,7 @@ CmdResult CommandFJoin::Handle(User* srcuser, Params& params)
 	// Process every member in the message
 	irc::spacesepstream users(params.back());
 	std::string item;
-	Modes::ChangeList* modechangelistptr = (apply_other_sides_modes ? &modechangelist : NULL);
+	Modes::ChangeList* modechangelistptr = (apply_other_sides_modes ? &modechangelist : nullptr);
 	while (users.GetToken(item))
 	{
 		ProcessModeUUIDPair(item, sourceserver, chan, modechangelistptr, fwdfjoin);
@@ -189,7 +189,7 @@ CmdResult CommandFJoin::Handle(User* srcuser, Params& params)
 
 	// Set prefix modes on their users if we lost the FJOIN or had equal TS
 	if (apply_other_sides_modes)
-		ServerInstance->Modes.Process(srcuser, chan, NULL, modechangelist, ModeParser::MODE_LOCALONLY);
+		ServerInstance->Modes.Process(srcuser, chan, nullptr, modechangelist, ModeParser::MODE_LOCALONLY);
 
 	return CmdResult::SUCCESS;
 }
@@ -233,7 +233,7 @@ void CommandFJoin::ProcessModeUUIDPair(const std::string& item, TreeServer* sour
 		}
 	}
 
-	Membership* memb = chan->ForceJoin(who, NULL, sourceserver->IsBursting());
+	Membership* memb = chan->ForceJoin(who, nullptr, sourceserver->IsBursting());
 	if (!memb)
 	{
 		// User was already on the channel, forward because of the modes they potentially got
@@ -264,7 +264,7 @@ void CommandFJoin::RemoveStatus(Channel* c)
 		mh->RemoveMode(c, changelist);
 	}
 
-	ServerInstance->Modes.Process(ServerInstance->FakeClient, c, NULL, changelist, ModeParser::MODE_LOCALONLY);
+	ServerInstance->Modes.Process(ServerInstance->FakeClient, c, nullptr, changelist, ModeParser::MODE_LOCALONLY);
 }
 
 void CommandFJoin::LowerTS(Channel* chan, time_t TS, const std::string& newname)
diff --git a/src/modules/m_spanningtree/fmode.cpp b/src/modules/m_spanningtree/fmode.cpp
index e59812efa..789342207 100644
--- a/src/modules/m_spanningtree/fmode.cpp
+++ b/src/modules/m_spanningtree/fmode.cpp
@@ -54,7 +54,7 @@ CmdResult CommandFMode::Handle(User* who, Params& params)
 	if ((TS == ourTS) && IS_SERVER(who))
 		flags |= ModeParser::MODE_MERGE;
 
-	ServerInstance->Modes.Process(who, chan, NULL, changelist, flags);
+	ServerInstance->Modes.Process(who, chan, nullptr, changelist, flags);
 	return CmdResult::SUCCESS;
 }
 
@@ -97,6 +97,6 @@ CmdResult CommandLMode::Handle(User* who, Params& params)
 	if (chants == chan->age && IS_SERVER(who))
 		flags |= ModeParser::MODE_MERGE;
 
-	ServerInstance->Modes.Process(who, chan, NULL, changelist, flags);
+	ServerInstance->Modes.Process(who, chan, nullptr, changelist, flags);
 	return CmdResult::SUCCESS;
 }
diff --git a/src/modules/m_spanningtree/ijoin.cpp b/src/modules/m_spanningtree/ijoin.cpp
index 1e756b115..625f0bdfc 100644
--- a/src/modules/m_spanningtree/ijoin.cpp
+++ b/src/modules/m_spanningtree/ijoin.cpp
@@ -49,7 +49,7 @@ CmdResult CommandIJoin::HandleRemote(RemoteUser* user, Params& params)
 		apply_modes = false;
 
 	// Join the user and set the membership id to what they sent
-	Membership* memb = chan->ForceJoin(user, apply_modes ? &params[3] : NULL);
+	Membership* memb = chan->ForceJoin(user, apply_modes ? &params[3] : nullptr);
 	if (!memb)
 		return CmdResult::FAILURE;
 
diff --git a/src/modules/m_spanningtree/main.cpp b/src/modules/m_spanningtree/main.cpp
index b2fa9c2d8..ad45a2746 100644
--- a/src/modules/m_spanningtree/main.cpp
+++ b/src/modules/m_spanningtree/main.cpp
@@ -532,7 +532,7 @@ void ModuleSpanningTree::OnUserJoin(Membership* memb, bool sync, bool created_by
 		params.add(memb);
 		params.finalize();
 		params.Broadcast();
-		Utils->SendListLimits(memb->chan, NULL);
+		Utils->SendListLimits(memb->chan, nullptr);
 	}
 	else
 	{
@@ -659,7 +659,7 @@ void ModuleSpanningTree::OnPreRehash(User* user, const std::string &parameter)
 	{
 		CmdBuilder params(user ? user : ServerInstance->FakeClient, "REHASH");
 		params.push(parameter);
-		params.Forward(user ? TreeServer::Get(user)->GetRoute() : NULL);
+		params.Forward(user ? TreeServer::Get(user)->GetRoute() : nullptr);
 	}
 }
 
diff --git a/src/modules/m_spanningtree/main.h b/src/modules/m_spanningtree/main.h
index d4edfebef..abbb21efd 100644
--- a/src/modules/m_spanningtree/main.h
+++ b/src/modules/m_spanningtree/main.h
@@ -154,7 +154,7 @@ public:
 
 	/** Connect a server locally
 	 */
-	void ConnectServer(std::shared_ptr<Link> x, std::shared_ptr<Autoconnect> y = NULL);
+	void ConnectServer(std::shared_ptr<Link> x, std::shared_ptr<Autoconnect> y = nullptr);
 
 	/** Connect the next autoconnect server
 	 */
diff --git a/src/modules/m_spanningtree/metadata.cpp b/src/modules/m_spanningtree/metadata.cpp
index 2119fae3e..bf7f47aa9 100644
--- a/src/modules/m_spanningtree/metadata.cpp
+++ b/src/modules/m_spanningtree/metadata.cpp
@@ -31,7 +31,7 @@ CmdResult CommandMetadata::Handle(User* srcuser, Params& params)
 	if (params[0] == "*")
 	{
 		std::string value = params.size() < 3 ? "" : params[2];
-		FOREACH_MOD(OnDecodeMetaData, (NULL,params[1],value));
+		FOREACH_MOD(OnDecodeMetaData, (nullptr, params[1], value));
 		return CmdResult::SUCCESS;
 	}
 
diff --git a/src/modules/m_spanningtree/postcommand.cpp b/src/modules/m_spanningtree/postcommand.cpp
index 4769d8a94..fe0857bd7 100644
--- a/src/modules/m_spanningtree/postcommand.cpp
+++ b/src/modules/m_spanningtree/postcommand.cpp
@@ -30,7 +30,7 @@
 void ModuleSpanningTree::OnPostCommand(Command* command, const CommandBase::Params& parameters, LocalUser* user, CmdResult result, bool loop)
 {
 	if (result == CmdResult::SUCCESS)
-		Utils->RouteCommand(NULL, command, parameters, user);
+		Utils->RouteCommand(nullptr, command, parameters, user);
 }
 
 void SpanningTreeUtilities::RouteCommand(TreeServer* origin, CommandBase* thiscmd, const CommandBase::Params& parameters, User* user)
@@ -105,7 +105,7 @@ void SpanningTreeUtilities::RouteCommand(TreeServer* origin, CommandBase* thiscm
 			std::string message;
 			if (parameters.size() >= 2)
 				message.assign(parameters[1]);
-			SendChannelMessage(user, c, message, pfx, parameters.GetTags(), exempts, command.c_str(), origin ? origin->GetSocket() : NULL);
+			SendChannelMessage(user, c, message, pfx, parameters.GetTags(), exempts, command.c_str(), origin ? origin->GetSocket() : nullptr);
 		}
 		else if (dest[0] == '$')
 		{
diff --git a/src/modules/m_spanningtree/protocolinterface.cpp b/src/modules/m_spanningtree/protocolinterface.cpp
index 6674b67b0..d8369089d 100644
--- a/src/modules/m_spanningtree/protocolinterface.cpp
+++ b/src/modules/m_spanningtree/protocolinterface.cpp
@@ -83,7 +83,7 @@ void SpanningTreeProtocolInterface::BroadcastEncap(const std::string& cmd, const
 
 	// If omit is non-NULL we pass the route belonging to the user to Forward(),
 	// otherwise we pass NULL, which is equivalent to Broadcast()
-	TreeServer* server = (omit ? TreeServer::Get(omit)->GetRoute() : NULL);
+	TreeServer* server = (omit ? TreeServer::Get(omit)->GetRoute() : nullptr);
 	CmdBuilder(source, "ENCAP * ").push_raw(cmd).insert(params).Forward(server);
 }
 
diff --git a/src/modules/m_spanningtree/server.cpp b/src/modules/m_spanningtree/server.cpp
index d8b0edc02..535299e72 100644
--- a/src/modules/m_spanningtree/server.cpp
+++ b/src/modules/m_spanningtree/server.cpp
@@ -101,7 +101,7 @@ std::shared_ptr<Link> TreeSocket::AuthRemote(const CommandBase::Params& params)
 	if (params.size() < 5)
 	{
 		SendError("Protocol error - Not enough parameters for SERVER command");
-		return NULL;
+		return nullptr;
 	}
 
 	const std::string& sname = params[0];
@@ -114,7 +114,7 @@ std::shared_ptr<Link> TreeSocket::AuthRemote(const CommandBase::Params& params)
 	if (!ServerInstance->IsSID(sid))
 	{
 		this->SendError("Invalid format server ID: "+sid+"!");
-		return NULL;
+		return nullptr;
 	}
 
 	for (std::shared_ptr<Link> x : Utils->LinkBlocks)
@@ -129,7 +129,7 @@ std::shared_ptr<Link> TreeSocket::AuthRemote(const CommandBase::Params& params)
 		}
 
 		if (!CheckDuplicate(sname, sid))
-			return NULL;
+			return nullptr;
 
 		const SSLIOHook* const ssliohook = SSLIOHook::IsSSL(this);
 		if (ssliohook)
@@ -141,7 +141,7 @@ std::shared_ptr<Link> TreeSocket::AuthRemote(const CommandBase::Params& params)
 		else if (capab->remotesa.family() != AF_UNIX && !irc::sockets::cidr_mask("127.0.0.0/8").match(capab->remotesa) && !irc::sockets::cidr_mask("::1/128").match(capab->remotesa))
 		{
 			this->SendError("Non-local server connections MUST be linked with SSL!");
-			return NULL;
+			return nullptr;
 		}
 
 		ServerInstance->SNO.WriteToSnoMask('l', "Verified server connection " + linkID + " ("+description+")");
@@ -150,7 +150,7 @@ std::shared_ptr<Link> TreeSocket::AuthRemote(const CommandBase::Params& params)
 
 	this->SendError("Mismatched server name or password (check the other server's snomask output for details - e.g. user mode +s +Ll)");
 	ServerInstance->SNO.WriteToSnoMask('l', "Server connection from \002"+sname+"\002 denied, invalid link credentials");
-	return NULL;
+	return nullptr;
 }
 
 /*
diff --git a/src/modules/m_spanningtree/servercommand.cpp b/src/modules/m_spanningtree/servercommand.cpp
index b4ce6775c..68f21a4aa 100644
--- a/src/modules/m_spanningtree/servercommand.cpp
+++ b/src/modules/m_spanningtree/servercommand.cpp
@@ -52,7 +52,7 @@ ServerCommand* ServerCommandManager::GetHandler(const std::string& command) cons
 	ServerCommandMap::const_iterator it = commands.find(command);
 	if (it != commands.end())
 		return it->second;
-	return NULL;
+	return nullptr;
 }
 
 bool ServerCommandManager::AddCommand(ServerCommand* cmd)
diff --git a/src/modules/m_spanningtree/treeserver.cpp b/src/modules/m_spanningtree/treeserver.cpp
index c55021e64..dabf064e6 100644
--- a/src/modules/m_spanningtree/treeserver.cpp
+++ b/src/modules/m_spanningtree/treeserver.cpp
@@ -37,8 +37,8 @@
  */
 TreeServer::TreeServer()
 	: Server(ServerInstance->Config->GetSID(), ServerInstance->Config->ServerName, ServerInstance->Config->ServerDesc)
-	, Parent(NULL), Route(NULL)
-	, Socket(NULL)
+	, Parent(nullptr), Route(nullptr)
+	, Socket(nullptr)
 	, behind_bursting(0)
 	, pingtimer(this)
 	, ServerUser(ServerInstance->FakeClient)
diff --git a/src/modules/m_spanningtree/treesocket.h b/src/modules/m_spanningtree/treesocket.h
index 27e96d50e..85e5de440 100644
--- a/src/modules/m_spanningtree/treesocket.h
+++ b/src/modules/m_spanningtree/treesocket.h
@@ -117,7 +117,7 @@ class TreeSocket final
 	std::unique_ptr<CapabData> capab;	/* Link setup data (held until burst is sent) */
 
 	/* The server we are talking to */
-	TreeServer* MyRoot = NULL;
+	TreeServer* MyRoot = nullptr;
 
 	/** Checks if the given servername and sid are both free
 	 */
diff --git a/src/modules/m_spanningtree/treesocket2.cpp b/src/modules/m_spanningtree/treesocket2.cpp
index 0f6cb5d33..bb5633988 100644
--- a/src/modules/m_spanningtree/treesocket2.cpp
+++ b/src/modules/m_spanningtree/treesocket2.cpp
@@ -272,7 +272,7 @@ User* TreeSocket::FindSource(const std::string& prefix, const std::string& comma
 	}
 
 	// Unknown prefix
-	return NULL;
+	return nullptr;
 }
 
 void TreeSocket::ProcessTag(User* source, const std::string& tag, ClientProtocol::TagMap& tags)
@@ -337,7 +337,7 @@ void TreeSocket::ProcessConnectedLine(std::string& taglist, std::string& prefix,
 
 	ServerCommand* scmd = Utils->Creator->CmdManager.GetHandler(command);
 	CommandBase* cmdbase = scmd;
-	Command* cmd = NULL;
+	Command* cmd = nullptr;
 	if (!scmd)
 	{
 		// Not a special server-to-server command
diff --git a/src/modules/m_spanningtree/uid.cpp b/src/modules/m_spanningtree/uid.cpp
index 1205880b2..7cf345dfd 100644
--- a/src/modules/m_spanningtree/uid.cpp
+++ b/src/modules/m_spanningtree/uid.cpp
@@ -112,12 +112,12 @@ CmdResult CommandUID::HandleServer(TreeServer* remoteserver, CommandBase::Params
 			 * yourself.
 			 */
 			Modes::Change modechange(mh, true, params[paramptr++]);
-			mh->OnModeChange(_new, _new, NULL, modechange);
+			mh->OnModeChange(_new, _new, nullptr, modechange);
 		}
 		else
 		{
 			Modes::Change modechange(mh, true, "");
-			mh->OnModeChange(_new, _new, NULL, modechange);
+			mh->OnModeChange(_new, _new, nullptr, modechange);
 		}
 		_new->SetMode(mh, true);
 	}
diff --git a/src/modules/m_spanningtree/utils.cpp b/src/modules/m_spanningtree/utils.cpp
index 1d42af1ea..3afe0fddb 100644
--- a/src/modules/m_spanningtree/utils.cpp
+++ b/src/modules/m_spanningtree/utils.cpp
@@ -34,7 +34,7 @@
 #include "resolvers.h"
 #include "commandbuilder.h"
 
-SpanningTreeUtilities* Utils = NULL;
+SpanningTreeUtilities* Utils = nullptr;
 
 ModResult ModuleSpanningTree::OnAcceptConnection(int newsock, ListenSocket* from, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 {
@@ -67,7 +67,7 @@ TreeServer* SpanningTreeUtilities::FindServer(const std::string &ServerName)
 	}
 	else
 	{
-		return NULL;
+		return nullptr;
 	}
 }
 
@@ -81,7 +81,7 @@ TreeServer* SpanningTreeUtilities::FindServerMask(const std::string &ServerName)
 		if (InspIRCd::Match(name, ServerName))
 			return server;
 	}
-	return NULL;
+	return nullptr;
 }
 
 TreeServer* SpanningTreeUtilities::FindServerID(const std::string &id)
@@ -90,7 +90,7 @@ TreeServer* SpanningTreeUtilities::FindServerID(const std::string &id)
 	if (iter != sidlist.end())
 		return iter->second;
 	else
-		return NULL;
+		return nullptr;
 }
 
 TreeServer* SpanningTreeUtilities::FindRouteTarget(const std::string& target)
@@ -103,7 +103,7 @@ TreeServer* SpanningTreeUtilities::FindRouteTarget(const std::string& target)
 	if (user)
 		return TreeServer::Get(user);
 
-	return NULL;
+	return nullptr;
 }
 
 SpanningTreeUtilities::SpanningTreeUtilities(ModuleSpanningTree* C)
@@ -350,7 +350,7 @@ std::shared_ptr<Link> SpanningTreeUtilities::FindLink(const std::string& name)
 			return x;
 		}
 	}
-	return NULL;
+	return nullptr;
 }
 
 void SpanningTreeUtilities::SendChannelMessage(User* source, Channel* target, const std::string& text, char status, const ClientProtocol::TagMap& tags, const CUList& exempt_list, const char* message_type, TreeSocket* omit)
diff --git a/src/modules/m_spanningtree/utils.h b/src/modules/m_spanningtree/utils.h
index ef97cdc9a..074c1c993 100644
--- a/src/modules/m_spanningtree/utils.h
+++ b/src/modules/m_spanningtree/utils.h
@@ -172,7 +172,7 @@ public:
 
 	/** Sends a PRIVMSG or a NOTICE to a channel obeying an exempt list and an optional prefix
 	 */
-	void SendChannelMessage(User* source, Channel* target, const std::string& text, char status, const ClientProtocol::TagMap& tags, const CUList& exempt_list, const char* message_type, TreeSocket* omit = NULL);
+	void SendChannelMessage(User* source, Channel* target, const std::string& text, char status, const ClientProtocol::TagMap& tags, const CUList& exempt_list, const char* message_type, TreeSocket* omit = nullptr);
 
 	// Builds link data to be sent to another server.
 	std::string BuildLinkString(uint16_t protocol, Module* mod);
diff --git a/src/modules/m_sslinfo.cpp b/src/modules/m_sslinfo.cpp
index 4ee937496..7a4601289 100644
--- a/src/modules/m_sslinfo.cpp
+++ b/src/modules/m_sslinfo.cpp
@@ -141,11 +141,11 @@ public:
 
 		LocalUser* luser = IS_LOCAL(user);
 		if (!luser || nosslext.Get(luser))
-			return NULL;
+			return nullptr;
 
 		cert = SSLClientCert::GetCertificate(&luser->eh);
 		if (!cert)
-			return NULL;
+			return nullptr;
 
 		SetCertificate(user, cert);
 		return cert;
@@ -402,7 +402,7 @@ public:
 	ModResult OnSetConnectClass(LocalUser* user, ConnectClass::Ptr myclass) override
 	{
 		ssl_cert* cert = cmd.sslapi.GetCertificate(user);
-		const char* error = NULL;
+		const char* error = nullptr;
 		const std::string requiressl = myclass->config->getString("requiressl");
 		if (stdalgo::string::equalsci(requiressl, "trusted"))
 		{
diff --git a/src/modules/m_starttls.cpp b/src/modules/m_starttls.cpp
index fc80b3e68..53819ce72 100644
--- a/src/modules/m_starttls.cpp
+++ b/src/modules/m_starttls.cpp
@@ -76,7 +76,7 @@ public:
 		 */
 		user->eh.DoWrite();
 
-		ssl->OnAccept(&user->eh, NULL, NULL);
+		ssl->OnAccept(&user->eh, nullptr, nullptr);
 
 		return CmdResult::SUCCESS;
 	}
diff --git a/src/modules/m_timedbans.cpp b/src/modules/m_timedbans.cpp
index 3fe06a0b9..09085dabb 100644
--- a/src/modules/m_timedbans.cpp
+++ b/src/modules/m_timedbans.cpp
@@ -122,7 +122,7 @@ public:
 
 		// Pass the user (instead of ServerInstance->FakeClient) to ModeHandler::Process() to
 		// make it so that the user sets the mode themselves
-		ServerInstance->Modes.Process(user, channel, NULL, setban);
+		ServerInstance->Modes.Process(user, channel, nullptr, setban);
 		if (ServerInstance->Modes.GetLastChangeList().empty())
 		{
 			user->WriteNotice("Invalid ban mask");
diff --git a/src/modules/m_websocket.cpp b/src/modules/m_websocket.cpp
index 64976f4ed..74f8b7b1a 100644
--- a/src/modules/m_websocket.cpp
+++ b/src/modules/m_websocket.cpp
@@ -465,7 +465,7 @@ class WebSocketHook final
 		key.append(MagicGUID);
 
 		std::string reply = "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: ";
-		reply.append(Base64::Encode((*sha1)->GenerateRaw(key), NULL, '=')).append(newline);
+		reply.append(Base64::Encode((*sha1)->GenerateRaw(key), nullptr, '=')).append(newline);
 		if (!selectedproto.empty())
 			reply.append("Sec-WebSocket-Protocol: ").append(selectedproto).append(newline);
 		reply.append(newline);
diff --git a/src/modules/m_xline_db.cpp b/src/modules/m_xline_db.cpp
index 8d9a8f936..f055ff804 100644
--- a/src/modules/m_xline_db.cpp
+++ b/src/modules/m_xline_db.cpp
@@ -224,7 +224,7 @@ public:
 				XLine* xl = xlf->Generate(ServerInstance->Time(), ConvToNum<unsigned long>(command_p[5]), command_p[3], command_p[6], command_p[2]);
 				xl->SetCreateTime(ConvToNum<time_t>(command_p[4]));
 
-				if (ServerInstance->XLines->AddLine(xl, NULL))
+				if (ServerInstance->XLines->AddLine(xl, nullptr))
 				{
 					ServerInstance->SNO.WriteToSnoMask('x', "database: Added a line of type %s", command_p[1].c_str());
 				}