diff --git a/dlls/quartz/enumpins.c b/dlls/quartz/enumpins.c
index 65e6759f920..61e42b08fbc 100644
--- a/dlls/quartz/enumpins.c
+++ b/dlls/quartz/enumpins.c
@@ -45,7 +45,7 @@ HRESULT IEnumPinsImpl_Construct(const ENUMPINDETAILS * pDetails, IEnumPins ** pp
     pEnumPins->lpVtbl = &IEnumPinsImpl_Vtbl;
     pEnumPins->refCount = 1;
     pEnumPins->uIndex = 0;
-    CopyMemory(&pEnumPins->enumPinDetails, pDetails, sizeof(ENUMPINDETAILS));
+    pEnumPins->enumPinDetails = *pDetails;
     *ppEnum = (IEnumPins *)(&pEnumPins->lpVtbl);
 
     TRACE("Created new enumerator (%p)\n", *ppEnum);
diff --git a/dlls/quartz/filesource.c b/dlls/quartz/filesource.c
index c75f9a2b9c3..d92208178db 100644
--- a/dlls/quartz/filesource.c
+++ b/dlls/quartz/filesource.c
@@ -237,8 +237,8 @@ static HRESULT GetClassMediaFile(IAsyncReader * pReader, LPCOLESTR pszFileName,
 
     TRACE("(%p, %s, %p, %p)\n", pReader, debugstr_w(pszFileName), majorType, minorType);
 
-    CopyMemory(majorType, &GUID_NULL, sizeof(*majorType));
-    CopyMemory(minorType, &GUID_NULL, sizeof(*minorType));
+    *majorType = GUID_NULL;
+    *minorType = GUID_NULL;
 
     lRet = RegOpenKeyExW(HKEY_CLASSES_ROOT, wszMediaType, 0, KEY_READ, &hkeyMediaType);
     hr = HRESULT_FROM_WIN32(lRet);