diff --git a/build.sh b/build.sh
index 882ce84..2bf2819 100755
--- a/build.sh
+++ b/build.sh
@@ -33,6 +33,15 @@ m['browser_specific_settings'] = {
     'data_collection_permissions': {'required': ['none']}
   }
 }
+# Firefox MV3 ne supporte pas (encore) 'service_worker' → AMO rejette.
+# On ajoute 'scripts' (event page) comme fallback compatible Firefox.
+# Chrome ignore 'scripts' quand 'service_worker' est présent ; Firefox
+# ignore 'service_worker' et utilise 'scripts'. Les deux navigateurs
+# chargent ainsi le même background.js.
+bg = m.get('background', {})
+if 'scripts' not in bg:
+    bg['scripts'] = ['background.js']
+m['background'] = bg
 with open('dist/firefox/manifest.json', 'w') as f:
   json.dump(m, f, indent=2, ensure_ascii=False)
   f.write('\n')
diff --git a/firefox-updates.json b/firefox-updates.json
index af5e44e..c56f119 100644
--- a/firefox-updates.json
+++ b/firefox-updates.json
@@ -5,7 +5,7 @@
         {
           "version": "2026.5.41",
           "update_link": "https://gitea.netaplaid.ch/FroSteel/Planification/releases/download/v2026.5.41/planification-v2026.5.41-firefox.xpi",
-          "update_hash": "sha256:ad7cd79ed50256e246d93c9fa87fda9db071fc19db14c363f90c3b3b446d3143"
+          "update_hash": "sha256:3cf688b6d38969100753f8911206b2a42589f7e6948ba75cae1d15fda4332411"
         },
         {
           "version": "2026.5.40",