diff --git a/dlls/strmbase/renderer.c b/dlls/strmbase/renderer.c
index dc1ece259ca..c06661ce73b 100644
--- a/dlls/strmbase/renderer.c
+++ b/dlls/strmbase/renderer.c
@@ -251,7 +251,7 @@ HRESULT WINAPI BaseRenderer_Init(BaseRenderer * This, const IBaseFilterVtbl *Vtb
     /* construct input pin */
     piInput.dir = PINDIR_INPUT;
     piInput.pFilter = &This->filter.IBaseFilter_iface;
-    lstrcpynW(piInput.achName, wcsInputPinName, sizeof(piInput.achName) / sizeof(piInput.achName[0]));
+    lstrcpynW(piInput.achName, wcsInputPinName, ARRAY_SIZE(piInput.achName));
 
     hr = BaseInputPin_Construct(&BaseRenderer_InputPin_Vtbl, sizeof(BaseInputPin), &piInput,
             &input_BaseInputFuncTable, &This->filter.csFilter, NULL, (IPin **)&This->pInputPin);
diff --git a/dlls/strmbase/transform.c b/dlls/strmbase/transform.c
index 8419b909318..2fdd2baf585 100644
--- a/dlls/strmbase/transform.c
+++ b/dlls/strmbase/transform.c
@@ -210,10 +210,10 @@ static HRESULT TransformFilter_Init(const IBaseFilterVtbl *pVtbl, const CLSID* p
     /* construct input pin */
     piInput.dir = PINDIR_INPUT;
     piInput.pFilter = &pTransformFilter->filter.IBaseFilter_iface;
-    lstrcpynW(piInput.achName, wcsInputPinName, sizeof(piInput.achName) / sizeof(piInput.achName[0]));
+    lstrcpynW(piInput.achName, wcsInputPinName, ARRAY_SIZE(piInput.achName));
     piOutput.dir = PINDIR_OUTPUT;
     piOutput.pFilter = &pTransformFilter->filter.IBaseFilter_iface;
-    lstrcpynW(piOutput.achName, wcsOutputPinName, sizeof(piOutput.achName) / sizeof(piOutput.achName[0]));
+    lstrcpynW(piOutput.achName, wcsOutputPinName, ARRAY_SIZE(piOutput.achName));
 
     hr = BaseInputPin_Construct(&TransformFilter_InputPin_Vtbl, sizeof(BaseInputPin), &piInput,
             &tf_input_BaseInputFuncTable, &pTransformFilter->filter.csFilter, NULL, &pTransformFilter->ppPins[0]);