diff --git a/src/factory/WFTaskFactory.inl b/src/factory/WFTaskFactory.inl
index 6687e0df..a526a867 100644
--- a/src/factory/WFTaskFactory.inl
+++ b/src/factory/WFTaskFactory.inl
@@ -303,45 +303,39 @@ void WFComplexClientTask<REQ, RESP, CTX>::init(TransportType type,
 template<class REQ, class RESP, typename CTX>
 bool WFComplexClientTask<REQ, RESP, CTX>::set_port()
 {
-	int port = 0;
-
-	if (uri_.port && uri_.port[0])
+	if (uri_.port)
 	{
-		port = atoi(uri_.port);
-		if (port < 0 || port > 65535)
+		int port = atoi(uri_.port);
+
+		if (port <= 0 || port > 65535)
 		{
 			this->state = WFT_STATE_TASK_ERROR;
 			this->error = WFT_ERR_URI_PORT_INVALID;
 			return false;
 		}
+
+		return true;
 	}
 
-	if (port == 0 && uri_.scheme)
+	if (uri_.scheme)
 	{
 		const char *port_str = WFGlobal::get_default_port(uri_.scheme);
 
 		if (port_str)
 		{
-			size_t port_len = strlen(port_str);
-
+			uri_.port = strdup(port_str);
 			if (uri_.port)
-				free(uri_.port);
+				return true;
 
-			uri_.port = (char *)malloc(port_len + 1);
-			if (!uri_.port)
-			{
-				uri_.state = URI_STATE_ERROR;
-				uri_.error = errno;
-				this->state = WFT_STATE_SYS_ERROR;
-				this->error = errno;
-				return false;
-			}
-
-			memcpy(uri_.port, port_str, port_len + 1);
+			this->state = WFT_STATE_SYS_ERROR;
+			this->error = errno;
+			return false;
 		}
 	}
 
-	return true;
+	this->state = WFT_STATE_TASK_ERROR;
+	this->error = WFT_ERR_URI_SCHEME_INVALID;
+	return false;
 }
 
 template<class REQ, class RESP, typename CTX>
diff --git a/src/manager/WFGlobal.cc b/src/manager/WFGlobal.cc
index a838cf5c..8bdd14da 100644
--- a/src/manager/WFGlobal.cc
+++ b/src/manager/WFGlobal.cc
@@ -60,19 +60,22 @@ public:
 		settings_ = *settings;
 	}
 
-	const char *get_default_port(const std::string& scheme) const
+	const char *get_default_port(const std::string& scheme)
 	{
 		const auto it = static_scheme_port_.find(scheme);
 
 		if (it != static_scheme_port_.end())
 			return it->second;
 
+		const char *port = NULL;
+		user_scheme_port_mutex_.lock();
 		const auto it2 = user_scheme_port_.find(scheme);
 
 		if (it2 != user_scheme_port_.end())
-			return it2->second.c_str();
+			port = it2->second.c_str();
 
-		return NULL;
+		user_scheme_port_mutex_.unlock();
+		return port;
 	}
 
 	void register_scheme_port(const std::string& scheme, unsigned short port)