diff --git a/dlls/strmbase/transform.c b/dlls/strmbase/transform.c
index b44becfc847..981a201c370 100644
--- a/dlls/strmbase/transform.c
+++ b/dlls/strmbase/transform.c
@@ -81,12 +81,12 @@ static HRESULT WINAPI TransformFilter_Input_Receive(BaseInputPin *This, IMediaSa
         return S_FALSE;
     }
 
+    LeaveCriticalSection(&pTransform->csReceive);
     if (pTransform->pFuncsTable->pfnReceive)
         hr = pTransform->pFuncsTable->pfnReceive(pTransform, pInSample);
     else
         hr = S_FALSE;
 
-    LeaveCriticalSection(&pTransform->csReceive);
     return hr;
 }