--- a/dom/html/HTMLCanvasElement.cpp
+++ b/dom/html/HTMLCanvasElement.cpp
@@ -125,16 +125,19 @@ public:
     }
 
     RefPtr<SourceSurface> snapshot = mOwningElement->GetSurfaceSnapshot(nullptr);
     if (!snapshot) {
       return;
     }
 
     RefPtr<DataSourceSurface> copy = CopySurface(snapshot);
+    if (!copy) {
+      return;
+    }
 
     mOwningElement->SetFrameCapture(copy.forget());
     mOwningElement->MarkContextCleanForFrameCapture();
   }
 
   void DetachFromRefreshDriver()
   {
     MOZ_ASSERT(mOwningElement);