diff --git a/dom/base/File.cpp b/dom/base/File.cpp
index 20fdb2580495..93611359c140 100644
--- a/dom/base/File.cpp
+++ b/dom/base/File.cpp
@@ -129,14 +129,11 @@ nsresult DataOwnerAdapter::Create(DataOwner* aDataOwner,
 NS_IMPL_CYCLE_COLLECTION_CLASS(File)
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(File)
-  // No unlink for mImpl bacause FileImpl is not CC-able.
-  tmp->mImpl = nullptr;
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(File)
-  // No traverse for mImpl bacause FileImpl is not CC-able.
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END