diff --git a/libs/backends/coreaudio/coreaudio_backend.h b/libs/backends/coreaudio/coreaudio_backend.h
index 6ccf1bf3f7..1c87e01c3a 100644
--- a/libs/backends/coreaudio/coreaudio_backend.h
+++ b/libs/backends/coreaudio/coreaudio_backend.h
@@ -397,7 +397,7 @@ class CoreAudioBackend : public AudioBackend, public PortEngineSharedImpl {
 #endif
 
 		ThreadData (CoreAudioBackend* e, boost::function<void ()> fp, size_t stacksz, double period)
-			: engine (e) , f (fp) , stacksize (stacksz), period_ns {}
+			: engine (e) , f (fp) , stacksize (stacksz), period_ns (period) {}
 	};
 
 	/* port engine */