diff --git a/dlls/quartz/avidec.c b/dlls/quartz/avidec.c
index 7f32288e8b..9e033c12f5 100644
--- a/dlls/quartz/avidec.c
+++ b/dlls/quartz/avidec.c
@@ -196,13 +196,13 @@ static HRESULT AVIDec_ConnectInput(TransformFilterImpl* pTransformFilter, const
 
             /* Copy bitmap header from media type to 1 for input and 1 for output */
             bih_size = format->bmiHeader.biSize + format->bmiHeader.biClrUsed * 4;
-            This->pBihIn = (BITMAPINFOHEADER*)CoTaskMemAlloc(bih_size);
+            This->pBihIn = CoTaskMemAlloc(bih_size);
             if (!This->pBihIn)
             {
                 hr = E_OUTOFMEMORY;
                 goto failed;
             }
-            This->pBihOut = (BITMAPINFOHEADER*)CoTaskMemAlloc(bih_size);
+            This->pBihOut = CoTaskMemAlloc(bih_size);
             if (!This->pBihOut)
             {
                 hr = E_OUTOFMEMORY;
diff --git a/dlls/quartz/enumregfilters.c b/dlls/quartz/enumregfilters.c
index 2e93c7b104..2816f08f86 100644
--- a/dlls/quartz/enumregfilters.c
+++ b/dlls/quartz/enumregfilters.c
@@ -67,7 +67,7 @@ HRESULT IEnumRegFiltersImpl_Construct(REGFILTER* pInRegFilters, const ULONG size
     for(i = 0; i < size; i++)
     {
         pRegFilters[i].Clsid = pInRegFilters[i].Clsid;
-        pRegFilters[i].Name = (WCHAR*)CoTaskMemAlloc((strlenW(pInRegFilters[i].Name)+1)*sizeof(WCHAR));
+        pRegFilters[i].Name = CoTaskMemAlloc((strlenW(pInRegFilters[i].Name)+1)*sizeof(WCHAR));
         if (!pRegFilters[i].Name)
         {
             while(i)
@@ -152,7 +152,7 @@ static HRESULT WINAPI IEnumRegFiltersImpl_Next(IEnumRegFilters * iface, ULONG cF
         for(i = 0; i < cFetched; i++)
         {
             /* The string in the REGFILTER structure must be allocated in the same block as the REGFILTER structure itself */
-            ppRegFilter[i] = (REGFILTER*)CoTaskMemAlloc(sizeof(REGFILTER)+(strlenW(This->RegFilters[i].Name)+1)*sizeof(WCHAR));
+            ppRegFilter[i] = CoTaskMemAlloc(sizeof(REGFILTER)+(strlenW(This->RegFilters[i].Name)+1)*sizeof(WCHAR));
             if (!ppRegFilter[i])
             {
                 while(i)
diff --git a/dlls/quartz/filtergraph.c b/dlls/quartz/filtergraph.c
index 02728d5a80..df1929d67f 100644
--- a/dlls/quartz/filtergraph.c
+++ b/dlls/quartz/filtergraph.c
@@ -327,11 +327,11 @@ static HRESULT WINAPI GraphBuilder_AddFilter(IGraphBuilder *iface,
     int i,j;
     WCHAR* wszFilterName = NULL;
     int duplicate_name = FALSE;
-    
+
     TRACE("(%p/%p)->(%p, %s (%p))\n", This, iface, pFilter, debugstr_w(pName), pName);
 
-    wszFilterName = (WCHAR*) CoTaskMemAlloc( (pName ? strlenW(pName) + 6 : 5) * sizeof(WCHAR) );
-    
+    wszFilterName = CoTaskMemAlloc( (pName ? strlenW(pName) + 6 : 5) * sizeof(WCHAR) );
+
     if (pName)
     {
 	/* Check if name already exists */
diff --git a/dlls/quartz/filtermapper.c b/dlls/quartz/filtermapper.c
index a45f477f4b..7f36fd2f5b 100644
--- a/dlls/quartz/filtermapper.c
+++ b/dlls/quartz/filtermapper.c
@@ -706,7 +706,7 @@ static HRESULT WINAPI FilterMapper2_RegisterFilter(
         regfilter2.dwVersion = 2;
         regfilter2.dwMerit = prf2->dwMerit;
         regfilter2.u.s1.cPins2 = prf2->u.s.cPins;
-        pregfp2 = (REGFILTERPINS2*) CoTaskMemAlloc(prf2->u.s.cPins * sizeof(REGFILTERPINS2));
+        pregfp2 = CoTaskMemAlloc(prf2->u.s.cPins * sizeof(REGFILTERPINS2));
         regfilter2.u.s1.rgPins2 = pregfp2;
         for (i = 0; i < prf2->u.s.cPins; i++)
         {
diff --git a/dlls/quartz/regsvr.c b/dlls/quartz/regsvr.c
index ced43bcac3..20bc5c4e73 100644
--- a/dlls/quartz/regsvr.c
+++ b/dlls/quartz/regsvr.c
@@ -588,7 +588,7 @@ static HRESULT register_filters(struct regsvr_filter const *list)
 	    rf2.dwVersion = 2;
 	    rf2.dwMerit = list->merit;
 	    rf2.u.s1.cPins2 = i;
-	    rf2.u.s1.rgPins2 = prfp2 = (REGFILTERPINS2*) CoTaskMemAlloc(i*sizeof(REGFILTERPINS2));
+	    rf2.u.s1.rgPins2 = prfp2 = CoTaskMemAlloc(i*sizeof(REGFILTERPINS2));
 	    if (!prfp2) {
 		hr = E_OUTOFMEMORY;
 		break;
@@ -600,7 +600,7 @@ static HRESULT register_filters(struct regsvr_filter const *list)
                 
 		for (nbmt = 0; list->pins[i].mediatypes[nbmt].majortype; nbmt++) ;
 		/* Allocate a single buffer for regpintypes struct and clsids */
-		lpMediatype = (REGPINTYPES*) CoTaskMemAlloc(nbmt*(sizeof(REGPINTYPES) + 2*sizeof(CLSID)));
+		lpMediatype = CoTaskMemAlloc(nbmt*(sizeof(REGPINTYPES) + 2*sizeof(CLSID)));
 		if (!lpMediatype) {
 		    hr = E_OUTOFMEMORY;
 		    break;