--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -7380,20 +7380,16 @@ nsLayoutUtils::SurfaceFromElement(HTMLCa
 
 nsLayoutUtils::SurfaceFromElementResult
 nsLayoutUtils::SurfaceFromElement(HTMLVideoElement* aElement,
                                   uint32_t aSurfaceFlags,
                                   RefPtr<DrawTarget>& aTarget)
 {
   SurfaceFromElementResult result;
 
-  NS_WARNING_ASSERTION(
-    (aSurfaceFlags & SFE_PREFER_NO_PREMULTIPLY_ALPHA) == 0,
-    "We can't support non-premultiplied alpha for video!");
-
   if (aElement->ContainsRestrictedContent()) {
     return result;
   }
 
   uint16_t readyState;
   if (NS_SUCCEEDED(aElement->GetReadyState(&readyState)) &&
       (readyState == nsIDOMHTMLMediaElement::HAVE_NOTHING ||
        readyState == nsIDOMHTMLMediaElement::HAVE_METADATA)) {