--- a/hghooks/mozhghooks/prevent_string_changes.py
+++ b/hghooks/mozhghooks/prevent_string_changes.py
@@ -33,17 +33,17 @@ def hook(ui, repo, hooktype, node, sourc
     if b'a=release' in repo[b'tip'].description().lower():
         # Accept the entire push for code uplifts
         return 0
     # Loop through each changeset being added to the repository
     for change_id in range(repo[node].rev(), len(repo)):
         # Loop through each file for the current changeset
         for file in repo[change_id].files():
             # Interested only in files potentially used for l10n
-            if (re.search(b'locales/en-US/', file) and file.endswith((b'.dtd', b'.ini', b'.properties'))):
+            if (re.search(b'locales/en-US/', file) and file.endswith((b'.dtd', b'.ftl', b'.ini', b'.properties'))):
                 changed_strings = True
                 if not re.search(b'l10n=', repo[b'tip'].description().lower()):
                     error += b"* File used for localization (%s) altered in this changeset *\n" % file
     # Check if an error occurred
     if error != b"":
         ui.write(b"\n************************** ERROR ****************************\n\n")
         ui.write(error)
         ui.write(b"\nThis repository is string frozen. Please request explicit permission from\n")

--- a/hghooks/tests/test-prevent-string-changes.t
+++ b/hghooks/tests/test-prevent-string-changes.t
@@ -65,30 +65,31 @@ Remove file (untracked extension, inside
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files
 
-Add file (tracked extension, inside expected path), wrong commit message, should fail
+Add DTD files (tracked extension, inside expected path), wrong commit message, should fail
 
   $ mkdir -p browser/locales/en-US
   $ echo "DTD file #1" >> browser/locales/en-US/test.dtd
   $ echo "DTD file #2" >> browser/locales/en-US/test2.dtd
   $ hg commit -A -m "Commit .dtd files inside l10n path, a=l10n"
   adding browser/locales/en-US/test.dtd
   adding browser/locales/en-US/test2.dtd
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 1 changesets with 2 changes to 2 files
   
   ************************** ERROR ****************************
   
   * File used for localization (browser/locales/en-US/test.dtd) altered in this changeset *
   * File used for localization (browser/locales/en-US/test2.dtd) altered in this changeset *
   
   This repository is string frozen. Please request explicit permission from
   release managers to break string freeze in your bug.
@@ -105,42 +106,84 @@ Amend commit message to use correct keyw
 
   $ hg -q commit --amend -m "Commit .dtd files inside l10n path, l10n=foo"
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 1 changesets with 2 changes to 2 files
   You've signaled approval for changes to strings in your push, thanks.
-  added 1 changesets with 2 changes to 2 files
+
+Add Fluent file (tracked extension, inside expected path), wrong commit message, should fail
+
+  $ mkdir -p browser/locales/en-US
+  $ echo "FTL file" >> browser/locales/en-US/test.ftl
+  $ hg commit -A -m "Commit .ftl files inside l10n path, a=l10n"
+  adding browser/locales/en-US/test.ftl
+  $ hg push ../server
+  pushing to ../server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  
+  ************************** ERROR ****************************
+  
+  * File used for localization (browser/locales/en-US/test.ftl) altered in this changeset *
+  
+  This repository is string frozen. Please request explicit permission from
+  release managers to break string freeze in your bug.
+  If you have that explicit permission, denote that by including in
+  your commit message l10n=...
+  *************************************************************
+  
+  transaction abort!
+  rollback completed
+  abort: pretxnchangegroup.prevent_string_changes hook failed
+  [255]
+
+Amend commit message to use correct keyword, should work
+
+  $ hg -q commit --amend -m "Commit .ftl files inside l10n path, l10n=foo"
+  $ hg push ../server
+  pushing to ../server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  You've signaled approval for changes to strings in your push, thanks.
 
 Edit existing file and commit with correct keyword, should work
 
   $ echo "Updated DTD content" >> browser/locales/en-US/test.dtd
   $ hg commit -A -m "Update .dtd file inside l10n path, l10n=foo"
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 1 changesets with 1 changes to 1 files
   You've signaled approval for changes to strings in your push, thanks.
-  added 1 changesets with 1 changes to 1 files
 
 Delete a file and commit without the correct keyword, should fail
 
   $ hg rm browser/locales/en-US/test.dtd
   $ hg commit -A -m "Remove .dtd file inside l10n path"
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 1 changesets with 0 changes to 0 files
   
   ************************** ERROR ****************************
   
   * File used for localization (browser/locales/en-US/test.dtd) altered in this changeset *
   
   This repository is string frozen. Please request explicit permission from
   release managers to break string freeze in your bug.
   If you have that explicit permission, denote that by including in
@@ -154,18 +197,18 @@ Delete a file and commit without the cor
 
   $ hg -q commit --amend -m "Remove .dtd file inside l10n path, l10n=foo"
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 1 changesets with 0 changes to 0 files
   You've signaled approval for changes to strings in your push, thanks.
-  added 1 changesets with 0 changes to 0 files
 
 Edit a file (tracked extension, inside expected path), as part of code uplift, should work
 
   $ echo "DTD file #1" >> browser/locales/en-US/test.dtd
   $ hg commit -A -m 'Change DTD file on trunk, no need of approval'
   adding browser/locales/en-US/test.dtd
   $ echo "uplift1" > dummy
   $ hg commit -A -m 'Doing code upload; a=release'
@@ -185,16 +228,17 @@ Same edit of a tracked file after releas
   $ echo "DTD file #1" >> browser/locales/en-US/test.dtd
   $ hg commit -m 'Change DTD file'
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 2 changesets with 2 changes to 2 files
   
   ************************** ERROR ****************************
   
   * File used for localization (browser/locales/en-US/test.dtd) altered in this changeset *
   
   This repository is string frozen. Please request explicit permission from
   release managers to break string freeze in your bug.
   If you have that explicit permission, denote that by including in
@@ -212,18 +256,18 @@ Message check should be case insensitive
   $ echo "DTD file #1" >> browser/locales/en-US/test.dtd
   $ hg commit -m 'Change DTD file, l10N='
   $ hg push ../server
   pushing to ../server
   searching for changes
   adding changesets
   adding manifests
   adding file changes
+  added 3 changesets with 3 changes to 2 files
   You've signaled approval for changes to strings in your push, thanks.
-  added 3 changesets with 3 changes to 2 files
 
   $ cd ..
 
 Hook should not run when stripping
 
   $ hg init striptest
   $ cd striptest
   $ echo initial > foo