diff --git a/browser/app/profile/channel-prefs.js b/browser/app/profile/channel-prefs.js
index 3850ec317ead..eed6e634c2b3 100644
--- a/browser/app/profile/channel-prefs.js
+++ b/browser/app/profile/channel-prefs.js
@@ -1,7 +1,7 @@
 /* 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/. */
-
+//
 // This pref is in its own file for complex reasons. See the comment in
 // browser/app/Makefile.in, bug 756325, and bug 1431342 for details. Do not add
 // other prefs to this file.
diff --git a/tools/update-verify/release/compare-directories.py b/tools/update-verify/release/compare-directories.py
index e56f99e1a6ff..7a171d08601c 100755
--- a/tools/update-verify/release/compare-directories.py
+++ b/tools/update-verify/release/compare-directories.py
@@ -38,6 +38,16 @@ TRANSFORMS = [
         'side': 'source',
         'deletion': '//@line 6 "',
     },
+    {
+        # warning comments from bug 1576546
+        'files': [
+            'defaults/pref/channel-prefs.js',
+            'Contents/Resources/defaults/pref/channel-prefs.js',
+        ],
+        'channel_prefix': ['aurora', 'beta', 'release', 'esr'],
+        'side': 'target',
+        'deletion': '//',
+    },
     {
         # updates from a beta to an RC build, the latter specifies the release channel
         'files': [