diff --git a/include/ha.h b/include/ha.h
index 4490d96..c577006 100644
--- a/include/ha.h
+++ b/include/ha.h
@@ -32,11 +32,12 @@ namespace Ha {
         }
     };
 
+    typedef void (*onMessage)(const char* msg);
     struct Command : Component {
         const char* commandTopic;
-        void (*f)(const char* msg);
+        onMessage f;
 
-        Command(const char* name, const char* uniqueId, const char* configTopic, const char* commandTopic, void (*f)(const char* msg)) : Component(name, uniqueId, configTopic) {
+        Command(const char* name, const char* uniqueId, const char* configTopic, const char* commandTopic, onMessage f) : Component(name, uniqueId, configTopic) {
             this->commandTopic = commandTopic;
             this->f = f;
         }