Index: gc_lang/fr/webext/background.js
==================================================================
--- gc_lang/fr/webext/background.js
+++ gc_lang/fr/webext/background.js
@@ -153,11 +153,11 @@
     },
 
     registerComposeScripts: async function () {
         // For Thunderbird only
         if (bThunderbird) {
-            let xRegisteredScripts = await browser.composeScripts.register({
+            let xRegisteredScripts = await messenger.composeScripts.register({
                 /*css: [
                     // Any number of code or file objects could be listed here.
                     { code: "body { background-color: red; }" },
                     { file: "compose.css" },
                 ],*/
@@ -367,11 +367,11 @@
 /*
     ComposeAction
     (Thunderbird only)
 */
 if (bThunderbird) {
-    browser.composeAction.onClicked.addListener(function (xTab, xData) {
+    messenger.composeAction.onClicked.addListener(function (xTab, xData) {
         sendCommandToTab(xTab.id, "grammar_checker_compose_window");
     });
 }