diff --git a/audio/include/audio/iaudiosink.h b/audio/include/audio/iaudiosink.h
index 1024e1d35..24a4d3e5b 100644
--- a/audio/include/audio/iaudiosink.h
+++ b/audio/include/audio/iaudiosink.h
@@ -106,6 +106,6 @@ public:
     virtual operator bool() const = 0;
 
 signals:
-    DECLARE_SIGNAL(finishedPlaying);
-    DECLARE_SIGNAL(invalidated);
+    DECLARE_SIGNAL(finishedPlaying, void);
+    DECLARE_SIGNAL(invalidated, void);
 };
diff --git a/audio/src/backend/alsink.h b/audio/src/backend/alsink.h
index 1ded9e4b4..8ada275b9 100644
--- a/audio/src/backend/alsink.h
+++ b/audio/src/backend/alsink.h
@@ -48,8 +48,8 @@ public:
     uint getSourceId() const;
     void kill();
 
-    SIGNAL_IMPL(AlSink, finishedPlaying)
-    SIGNAL_IMPL(AlSink, invalidated)
+    SIGNAL_IMPL(AlSink, finishedPlaying, void)
+    SIGNAL_IMPL(AlSink, invalidated, void)
 
 private:
     OpenAL& audio;