diff --git a/src/audio/backend/alsink.h b/src/audio/backend/alsink.h
index b742bba13..6174824d0 100644
--- a/src/audio/backend/alsink.h
+++ b/src/audio/backend/alsink.h
@@ -49,8 +49,8 @@ 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;
diff --git a/src/audio/iaudiosink.h b/src/audio/iaudiosink.h
index 83f53c1b1..faf35474a 100644
--- a/src/audio/iaudiosink.h
+++ b/src/audio/iaudiosink.h
@@ -107,8 +107,8 @@ public:
     virtual operator bool() const = 0;
 
 signals:
-    DECLARE_SIGNAL(finishedPlaying);
-    DECLARE_SIGNAL(invalidated);
+    DECLARE_SIGNAL(finishedPlaying, void);
+    DECLARE_SIGNAL(invalidated, void);
 };
 
 #endif // IAUDIOSINK_H