diff --git a/image/src/imgFrame.cpp b/image/src/imgFrame.cpp
index 904929f4d7d..ebd44e1280c 100644
--- a/image/src/imgFrame.cpp
+++ b/image/src/imgFrame.cpp
@@ -291,7 +291,6 @@ nsresult imgFrame::Optimize()
 #ifdef XP_MACOSX
   if (mQuartzSurface) {
     mQuartzSurface->Flush();
-    mOptSurface = mQuartzSurface;
   }
 #endif