diff --git a/dlls/dmsynth/dmsynth_private.h b/dlls/dmsynth/dmsynth_private.h
index ed86ce0914b..db61e46464b 100644
--- a/dlls/dmsynth/dmsynth_private.h
+++ b/dlls/dmsynth/dmsynth_private.h
@@ -66,7 +66,7 @@ struct IDirectMusicSynth8Impl {
     DMUS_PORTCAPS pCaps;
     BOOL fActive;
     IReferenceClock* pLatencyClock;
-    IDirectMusicSynthSinkImpl* pSynthSink;
+    IDirectMusicSynthSink *synth_sink;
 };
 
 /*****************************************************************************
diff --git a/dlls/dmsynth/synth.c b/dlls/dmsynth/synth.c
index 88ba53ea475..afeebda45b6 100644
--- a/dlls/dmsynth/synth.c
+++ b/dlls/dmsynth/synth.c
@@ -310,7 +310,7 @@ static HRESULT WINAPI IDirectMusicSynth8Impl_GetLatencyClock(LPDIRECTMUSICSYNTH8
     if (!clock)
         return E_POINTER;
 
-    if (!This->pSynthSink)
+    if (!This->synth_sink)
         return DMUS_E_NOSYNTHSINK;
 
     *clock = This->pLatencyClock;
@@ -336,7 +336,7 @@ static HRESULT WINAPI IDirectMusicSynth8Impl_SetSynthSink(LPDIRECTMUSICSYNTH8 if
 
     TRACE("(%p)->(%p)\n", iface, synth_sink);
 
-    This->pSynthSink = (IDirectMusicSynthSinkImpl*)synth_sink;
+    This->synth_sink = synth_sink;
 
     if (synth_sink)
         return IDirectMusicSynthSink_GetLatencyClock(synth_sink, &This->pLatencyClock);