--- a/dom/media/MediaInfo.h
+++ b/dom/media/MediaInfo.h
@@ -256,17 +256,17 @@ public:
   // If aWidth and aHeight are identical to the original mImage.width/mImage.height
   // then the scaling ratio will be 1.
   // This is used for when the frame size is different from what the container
   // reports. This is legal in WebM, and we will preserve the ratio of the crop
   // rectangle as it was reported relative to the picture size reported by the
   // container.
   nsIntRect ScaledImageRect(int64_t aWidth, int64_t aHeight) const
   {
-    if (aWidth == mImage.width && aHeight == mImage.height) {
+    if (aWidth == mImage.width || aHeight == mImage.height) {
       return ImageRect();
     }
     nsIntRect imageRect = ImageRect();
     imageRect.x = (imageRect.x * aWidth) / mImage.width;
     imageRect.y = (imageRect.y * aHeight) / mImage.height;
     imageRect.width = (aWidth * imageRect.width) / mImage.width;
     imageRect.height = (aHeight * imageRect.height) / mImage.height;
     return imageRect;