--- a/image/decoders/nsICODecoder.cpp
+++ b/image/decoders/nsICODecoder.cpp
@@ -207,19 +207,19 @@ nsICODecoder::ExtractBIHSizeFromBitmap(i
 
 void
 nsICODecoder::SetHotSpotIfCursor() {
   if (!mIsCursor) {
     return;
   }
 
   nsCOMPtr<nsISupportsPRUint32> intwrapx = 
-    do_CreateInstance("@mozilla.org/supports-uint32_t;1");
+    do_CreateInstance("@mozilla.org/supports-PRUint32;1");
   nsCOMPtr<nsISupportsPRUint32> intwrapy = 
-    do_CreateInstance("@mozilla.org/supports-uint32_t;1");
+    do_CreateInstance("@mozilla.org/supports-PRUint32;1");
 
   if (intwrapx && intwrapy) {
     intwrapx->SetData(mDirEntry.mXHotspot);
     intwrapy->SetData(mDirEntry.mYHotspot);
 
     mImage.Set("hotspotX", intwrapx);
     mImage.Set("hotspotY", intwrapy);
   }