diff --git a/editor/composer/moz.build b/editor/composer/moz.build
index 23119de73002..e4d92a0308bb 100644
--- a/editor/composer/moz.build
+++ b/editor/composer/moz.build
@@ -16,7 +16,6 @@ XPIDL_MODULE = 'composer'
 
 UNIFIED_SOURCES += [
     'ComposerCommandsUpdater.cpp',
-    'nsComposerRegistration.cpp',
     'nsEditingSession.cpp',
 ]
 
diff --git a/editor/composer/nsComposerRegistration.cpp b/editor/composer/nsComposerRegistration.cpp
deleted file mode 100644
index 4775c4ca87cd..000000000000
--- a/editor/composer/nsComposerRegistration.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "mozilla/HTMLEditorController.h" // for HTMLEditorController, etc
-#include "mozilla/Module.h"             // for Module, Module::CIDEntry, etc
-#include "mozilla/ModuleUtils.h"
-#include "mozilla/mozalloc.h"           // for operator new
-#include "nsCOMPtr.h"                   // for nsCOMPtr, getter_AddRefs, etc
-#include "nsBaseCommandController.h"    // for nsBaseCommandController
-#include "nsComponentManagerUtils.h"    // for do_CreateInstance
-#include "nsDebug.h"                    // for NS_ENSURE_SUCCESS
-#include "nsError.h"                    // for NS_ERROR_NO_AGGREGATION, etc
-#include "nsIController.h"              // for nsIController
-#include "nsIControllerContext.h"       // for nsIControllerContext
-#include "nsID.h"                       // for NS_DEFINE_NAMED_CID, etc
-#include "nsISupportsImpl.h"
-#include "nsISupportsUtils.h"           // for NS_ADDREF, NS_RELEASE
-#include "nsControllerCommandTable.h"   // for nsControllerCommandTable, etc
-#include "nsServiceManagerUtils.h"      // for do_GetService
-#include "nscore.h"                     // for nsresult
-
-class nsISupports;
-
-////////////////////////////////////////////////////////////////////////
-// Define the contructor function for the objects
-//
-// NOTE: This creates an instance of objects by using the default constructor
-//
-
-static const mozilla::Module::CIDEntry kComposerCIDs[] = {
-  { nullptr }
-};
-
-static const mozilla::Module::ContractIDEntry kComposerContracts[] = {
-  { nullptr }
-};
-
-static const mozilla::Module kComposerModule = {
-  mozilla::Module::kVersion,
-  kComposerCIDs,
-  kComposerContracts
-};
-
-NSMODULE_DEFN(nsComposerModule) = &kComposerModule;