diff --git a/include/async_mqtt5/impl/client_service.hpp b/include/async_mqtt5/impl/client_service.hpp
index a35e42a..f03f3bb 100644
--- a/include/async_mqtt5/impl/client_service.hpp
+++ b/include/async_mqtt5/impl/client_service.hpp
@@ -71,26 +71,32 @@ public:
 		_mqtt_context.will_msg = std::move(will);
 	}
 
-	template <typename Prop>
-	const auto& connack_property(Prop p) const {
-		return _mqtt_context.ca_props[p];
+	template <prop::property_type p>
+	const auto& connack_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _mqtt_context.ca_props[prop];
 	}
 
 	const auto& connack_properties() const {
 		return _mqtt_context.ca_props;
 	}
 
-	template <typename Prop>
-	const auto& connect_property(Prop p) const {
-		return _mqtt_context.co_props[p];
+	template <prop::property_type p>
+	const auto& connect_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _mqtt_context.co_props[prop];
 	}
 
-	template <typename Prop>
-	auto& connect_property(Prop p) {
-		return _mqtt_context.co_props[p];
+	template <prop::property_type p>
+	auto& connect_property(
+		std::integral_constant<prop::property_type, p> prop
+	) {
+		return _mqtt_context.co_props[prop];
 	}
 
-	void connect_propertiess(connect_props props) {
+	void connect_properties(connect_props props) {
 		_mqtt_context.co_props = std::move(props);
 	}
 
@@ -144,23 +150,29 @@ public:
 		_mqtt_context.will_msg = std::move(will);
 	}
 
-	template <typename Prop>
-	const auto& connack_property(Prop p) const {
-		return _mqtt_context.ca_props[p];
+	template <prop::property_type p>
+	const auto& connack_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _mqtt_context.ca_props[prop];
 	}
 
 	const auto& connack_properties() const {
 		return _mqtt_context.ca_props;
 	}
 
-	template <typename Prop>
-	const auto& connect_property(Prop p) const {
-		return _mqtt_context.co_props[p];
+	template <prop::property_type p>
+	const auto& connect_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _mqtt_context.co_props[prop];
 	}
 
-	template <typename Prop>
-	auto& connect_property(Prop p) {
-		return _mqtt_context.co_props[p];
+	template <prop::property_type p>
+	auto& connect_property(
+		std::integral_constant<prop::property_type, p> prop
+	) {
+		return _mqtt_context.co_props[prop];
 	}
 
 	void connect_properties(connect_props props) {
@@ -323,14 +335,20 @@ public:
 			_stream_context.mqtt_context().keep_alive = seconds;
 	}
 
-	template <typename Prop>
-	const auto& connect_property(Prop p) const {
-		return _stream_context.connect_property(p);
+	template <prop::property_type p>
+	const auto& connect_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _stream_context.connect_property(prop);
 	}
 
-	template <typename Prop>
-	auto& connect_property(Prop p) {
-		return _stream_context.connect_property(p);
+	template <prop::property_type p>
+	void connect_property(
+		std::integral_constant<prop::property_type, p> prop,
+		prop::value_type_t<p> value
+	){
+		if (!is_open())
+			_stream_context.connect_property(prop) = value;
 	}
 
 	void connect_properties(connect_props props) {
@@ -338,9 +356,11 @@ public:
 			_stream_context.connect_properties(std::move(props));
 	}
 
-	template <typename Prop>
-	const auto& connack_property(Prop p) const {
-		return _stream_context.connack_property(p);
+	template <prop::property_type p>
+	const auto& connack_property(
+		std::integral_constant<prop::property_type, p> prop
+	) const {
+		return _stream_context.connack_property(prop);
 	}
 
 	const auto& connack_properties() const {
diff --git a/include/async_mqtt5/mqtt_client.hpp b/include/async_mqtt5/mqtt_client.hpp
index 3ec6aea..a9a98ef 100644
--- a/include/async_mqtt5/mqtt_client.hpp
+++ b/include/async_mqtt5/mqtt_client.hpp
@@ -349,7 +349,7 @@ public:
 		std::integral_constant<prop::property_type, p> prop,
 		prop::value_type_t<p> value
 	) {
-		_impl->connect_property(prop) = value;
+		_svc_ptr->connect_property(prop, std::move(value));
 		return *this;
 	}
 
diff --git a/include/async_mqtt5/types.hpp b/include/async_mqtt5/types.hpp
index f084536..eec6786 100644
--- a/include/async_mqtt5/types.hpp
+++ b/include/async_mqtt5/types.hpp
@@ -282,6 +282,10 @@ class will : public will_props {
 public:
 	/**
 	 * \brief Constructs an empty Will Message.
+	 *
+	 * \attention Do not use!
+	 * An empty Will Message results in an empty Topic Name which is not valid.
+	 * Internal uses only.
 	 */
 	will() = default;