diff --git a/dlls/mmdevapi/audiovolume.c b/dlls/mmdevapi/audiovolume.c
index 194cfa37f10..7dddbdf1660 100644
--- a/dlls/mmdevapi/audiovolume.c
+++ b/dlls/mmdevapi/audiovolume.c
@@ -40,8 +40,6 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(mmdevapi);
 
-static const IAudioEndpointVolumeExVtbl AEVImpl_Vtbl;
-
 typedef struct AEVImpl {
     IAudioEndpointVolumeEx IAudioEndpointVolumeEx_iface;
     LONG ref;
@@ -52,18 +50,6 @@ static inline AEVImpl *impl_from_IAudioEndpointVolumeEx(IAudioEndpointVolumeEx *
     return CONTAINING_RECORD(iface, AEVImpl, IAudioEndpointVolumeEx_iface);
 }
 
-HRESULT AudioEndpointVolume_Create(MMDevice *parent, IAudioEndpointVolume **ppv)
-{
-    AEVImpl *This;
-    This = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*This));
-    *ppv = (IAudioEndpointVolume*)This;
-    if (!This)
-        return E_OUTOFMEMORY;
-    This->IAudioEndpointVolumeEx_iface.lpVtbl = &AEVImpl_Vtbl;
-    This->ref = 1;
-    return S_OK;
-}
-
 static void AudioEndpointVolume_Destroy(AEVImpl *This)
 {
     HeapFree(GetProcessHeap(), 0, This);
@@ -79,7 +65,7 @@ static HRESULT WINAPI AEV_QueryInterface(IAudioEndpointVolumeEx *iface, REFIID r
     if (IsEqualIID(riid, &IID_IUnknown) ||
         IsEqualIID(riid, &IID_IAudioEndpointVolume) ||
         IsEqualIID(riid, &IID_IAudioEndpointVolumeEx)) {
-        *ppv = This;
+        *ppv = &This->IAudioEndpointVolumeEx_iface;
     }
     else
         return E_NOINTERFACE;
@@ -286,3 +272,18 @@ static const IAudioEndpointVolumeExVtbl AEVImpl_Vtbl = {
     AEV_GetVolumeRange,
     AEV_GetVolumeRangeChannel
 };
+
+HRESULT AudioEndpointVolume_Create(MMDevice *parent, IAudioEndpointVolume **ppv)
+{
+    AEVImpl *This;
+
+    *ppv = NULL;
+    This = HeapAlloc(GetProcessHeap(), 0, sizeof(*This));
+    if (!This)
+        return E_OUTOFMEMORY;
+    This->IAudioEndpointVolumeEx_iface.lpVtbl = &AEVImpl_Vtbl;
+    This->ref = 1;
+
+    *ppv = (IAudioEndpointVolume*)&This->IAudioEndpointVolumeEx_iface;
+    return S_OK;
+}
diff --git a/dlls/mmdevapi/devenum.c b/dlls/mmdevapi/devenum.c
index 1952bda2f02..d50d20671af 100644
--- a/dlls/mmdevapi/devenum.c
+++ b/dlls/mmdevapi/devenum.c
@@ -551,7 +551,7 @@ static HRESULT WINAPI MMDevice_QueryInterface(IMMDevice *iface, REFIID riid, voi
     *ppv = NULL;
     if (IsEqualIID(riid, &IID_IUnknown)
         || IsEqualIID(riid, &IID_IMMDevice))
-        *ppv = This;
+        *ppv = &This->IMMDevice_iface;
     else if (IsEqualIID(riid, &IID_IMMEndpoint))
         *ppv = &This->IMMEndpoint_iface;
     if (*ppv)
@@ -797,7 +797,7 @@ static HRESULT WINAPI MMDevCol_QueryInterface(IMMDeviceCollection *iface, REFIID
         return E_POINTER;
     if (IsEqualIID(riid, &IID_IUnknown)
         || IsEqualIID(riid, &IID_IMMDeviceCollection))
-        *ppv = This;
+        *ppv = &This->IMMDeviceCollection_iface;
     else
         *ppv = NULL;
     if (!*ppv)
@@ -897,7 +897,7 @@ HRESULT MMDevEnum_Create(REFIID riid, void **ppv)
         load_driver_devices(eRender);
         load_driver_devices(eCapture);
     }
-    return IUnknown_QueryInterface((IUnknown*)This, riid, ppv);
+    return IMMDeviceEnumerator_QueryInterface(&This->IMMDeviceEnumerator_iface, riid, ppv);
 }
 
 void MMDevEnum_Free(void)
@@ -920,7 +920,7 @@ static HRESULT WINAPI MMDevEnum_QueryInterface(IMMDeviceEnumerator *iface, REFII
         return E_POINTER;
     if (IsEqualIID(riid, &IID_IUnknown)
         || IsEqualIID(riid, &IID_IMMDeviceEnumerator))
-        *ppv = This;
+        *ppv = &This->IMMDeviceEnumerator_iface;
     else
         *ppv = NULL;
     if (!*ppv)
@@ -1345,7 +1345,7 @@ static HRESULT WINAPI MMDevPropStore_QueryInterface(IPropertyStore *iface, REFII
         return E_POINTER;
     if (IsEqualIID(riid, &IID_IUnknown)
         || IsEqualIID(riid, &IID_IPropertyStore))
-        *ppv = This;
+        *ppv = &This->IPropertyStore_iface;
     else
         *ppv = NULL;
     if (!*ppv)