--- a/.taskcluster.yml
+++ b/.taskcluster.yml
@@ -101,17 +101,17 @@ tasks:
       retries: 5
 
       payload:
         env:
           # checkout-gecko uses these to check out the source; the inputs
           # to `mach taskgraph decision` are all on the command line.
           $merge:
             - GECKO_BASE_REPOSITORY: 'https://hg.mozilla.org/mozilla-unified'
-              GECKO_HEAD_REPOSITORY: 'https://hg.mozilla.org/releases/mozilla-beta'
+              GECKO_HEAD_REPOSITORY: 'https://hg.mozilla.org/releases/mozilla-release'
               GECKO_HEAD_REF: 'ef5478ee0f0a'
               COMM_BASE_REPOSITORY: 'https://hg.mozilla.org/comm-central'
               COMM_HEAD_REPOSITORY: '${repoUrl}'
               COMM_HEAD_REF: '${push.revision}'
               COMM_HEAD_REV: '${push.revision}'
               HG_STORE_PATH: /builds/worker/checkouts/hg-store
               TASKCLUSTER_CACHES: /builds/worker/checkouts
             - $if: 'tasks_for != "action"'

--- a/mail/confvars.sh
+++ b/mail/confvars.sh
@@ -17,19 +17,19 @@ BROWSER_CHROME_URL=chrome://messenger/co
 
 MOZ_BRANDING_DIRECTORY=$commreltopsrcdir/mail/branding/nightly
 MOZ_OFFICIAL_BRANDING_DIRECTORY=$commreltopsrcdir/mail/branding/thunderbird
 
 MOZ_APP_ID={3550f703-e582-4d05-9a08-453d09bdfdc6}
 # This should usually be the same as the value MAR_CHANNEL_ID.
 # If more than one ID is needed, then you should use a comma separated list
 # of values.
-ACCEPTED_MAR_CHANNEL_IDS=thunderbird-comm-beta,thunderbird-comm-release
+ACCEPTED_MAR_CHANNEL_IDS=thunderbird-comm-release
 # The MAR_CHANNEL_ID must not contain the following 3 characters: ",\t "
-MAR_CHANNEL_ID=thunderbird-comm-beta
+MAR_CHANNEL_ID=thunderbird-comm-release
 MOZ_PROFILE_MIGRATOR=1
 MOZ_BINARY_EXTENSIONS=1
 MOZ_SEPARATE_MANIFEST_FOR_THEME_OVERRIDES=1
 
 # Enable building ./signmar and running libmar signature tests
 MOZ_ENABLE_SIGNMAR=1
 
 MOZ_DEVTOOLS=all