diff --git a/src/TinyMqtt.cpp b/src/TinyMqtt.cpp
index da96ee1..74ca4b1 100644
--- a/src/TinyMqtt.cpp
+++ b/src/TinyMqtt.cpp
@@ -672,6 +672,7 @@ void MqttMessage::add(const char* p, size_t len, bool addLength)
 {
 	if (addLength)
 	{
+		buffer.reserve(buffer.length()+addLength+2);
 		incoming(len>>8);
 		incoming(len & 0xFF);
 	}
diff --git a/src/TinyMqtt.h b/src/TinyMqtt.h
index ee9692e..d6dc2db 100644
--- a/src/TinyMqtt.h
+++ b/src/TinyMqtt.h
@@ -80,23 +80,15 @@ class MqttMessage
 		// output buff+=2, len=length(str)
 		static void getString(const char* &buff, uint16_t& len);
 
-
 		Type type() const
 		{
 			return state == Complete ? static_cast<Type>(buffer[0]) : Unknown;
 		}
 
-		// shouldn't exist because it breaks constness :-(
-		// but this saves memory so ...
-		void changeType(Type type) const
-		{
-			buffer[0] = type;
-		}
-
 		void create(Type type)
 		{
 			buffer=(char)type;
-			buffer+='\0';
+			buffer+='\0';		// reserved for msg length
 			vheader=2;
 			size=0;
 			state=Create;
diff --git a/tests/Makefile b/tests/Makefile
index bfea400..e2d6bac 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -5,7 +5,7 @@ tests:
 		$(MAKE) -C $$(dirname $$i) -j; \
 	done
 
-runtests:
+runtests: tests
 	set -e; \
 	for i in *-tests/Makefile; do \
 		echo '==== Running:' $$(dirname $$i); \