diff --git a/app.py b/app.py
index 10eeed558..ed7e5bdac 100644
--- a/app.py
+++ b/app.py
@@ -498,8 +498,8 @@ def app_install(auth, app, label=None, args=None):
             raise MoulinetteError(errno.EINTR, m18n.g('operation_interrupted'))
         except Exception as e:
             import traceback
-            msignals.display(traceback.format_exc(), 'log')
-            raise MoulinetteError(errno.EIO, m18n.n('installation_failed'))
+            msignals.display(traceback.format_exc().strip(), 'log')
+            raise MoulinetteError(errno.EIO, m18n.n('unexpected_error'))
 
 
 def app_remove(auth, app):
diff --git a/locales/en.json b/locales/en.json
index a0a3cb71e..5355bb80b 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -5,6 +5,7 @@
     "upgrade_complete" : "Upgrade complete",
     "installation_complete" : "Installation complete",
     "installation_failed" : "Installation failed",
+    "unexpected_error" : "An unexpected error occured",
 
     "license_undefined" : "undefined",
     "no_appslist_found" : "No apps list found",
diff --git a/locales/fr.json b/locales/fr.json
index f4844d129..678894a7d 100644
--- a/locales/fr.json
+++ b/locales/fr.json
@@ -5,6 +5,7 @@
     "upgrade_complete" : "Mise à jour terminée",
     "installation_complete" : "Installation terminée",
     "installation_failed" : "Échec de l'installation",
+    "unexpected_error" : "Une erreur inattendue est survenue",
 
     "license_undefined" : "indéfinie",
     "no_appslist_found" : "Aucune liste d'applications trouvée",