--- a/gfx/thebes/gfxContext.cpp
+++ b/gfx/thebes/gfxContext.cpp
@@ -849,19 +849,19 @@ gfxContext::PushGroupAndCopyBackground(g
     Save();
 
     if (pushOpaqueWithCopiedBG) {
       mDT->PushLayer(true, aOpacity, aMask, aMaskTransform, IntRect(), true);
     } else {
       mDT->PushLayer(content == gfxContentType::COLOR, aOpacity, aMask, aMaskTransform, IntRect(), false);
     }
   } else {
-    if (pushOpaqueWithCopiedBG) {
+    RefPtr<SourceSurface> source;
+    if (pushOpaqueWithCopiedBG && (source = mDT->Snapshot())) {
       DrawTarget *oldDT = mDT;
-      RefPtr<SourceSurface> source = mDT->Snapshot();
       Point oldDeviceOffset = CurrentState().deviceOffset;
 
       PushNewDT(gfxContentType::COLOR);
 
       if (oldDT == mDT) {
         // Creating new DT failed.
         return;
       }