--- a/media/gmp-clearkey/0.1/WMFH264Decoder.cpp
+++ b/media/gmp-clearkey/0.1/WMFH264Decoder.cpp
@@ -153,17 +153,20 @@ WMFH264Decoder::SetDecoderOutputType()
 
   UINT32 typeIndex = 0;
   while (type = nullptr, SUCCEEDED(mDecoder->GetOutputAvailableType(0, typeIndex++, &type))) {
     GUID subtype;
     hr = type->GetGUID(MF_MT_SUBTYPE, &subtype);
     if (FAILED(hr)) {
       continue;
     }
-    if (subtype == MFVideoFormat_I420) {
+    if (subtype == MFVideoFormat_I420 || subtype == MFVideoFormat_IYUV) {
+      // On Windows 7 Enterprise N the MFT reports it reports IYUV instead
+      // of I420. Other Windows' report I420. The formats are the same, so
+      // support both.
       hr = mDecoder->SetOutputType(0, type, 0);
       ENSURE(SUCCEEDED(hr), hr);
 
       hr = ConfigureVideoFrameGeometry(type);
       ENSURE(SUCCEEDED(hr), hr);
 
       return S_OK;
     }