diff --git a/bin/addons/base/i18n/base.pot b/bin/addons/base/i18n/base.pot
index f0ad2bf8207..d96c081d6a6 100644
--- a/bin/addons/base/i18n/base.pot
+++ b/bin/addons/base/i18n/base.pot
@@ -8746,7 +8746,7 @@ msgstr ""
 #. module: base
 #: code:addons/base/module/wizard/base_module_upgrade.py:0
 #, python-format
-msgid "Following modules are uninstalled or unknown. \n\n'+'\n'.join(unmet_packages)"
+msgid "Following modules are not installed or unknown: %s"
 msgstr ""
 
 #. module: base
diff --git a/bin/addons/base/module/wizard/base_module_upgrade.py b/bin/addons/base/module/wizard/base_module_upgrade.py
index b791aeea459..de9df1ec3e0 100644
--- a/bin/addons/base/module/wizard/base_module_upgrade.py
+++ b/bin/addons/base/module/wizard/base_module_upgrade.py
@@ -93,7 +93,7 @@ class base_module_upgrade(osv.osv_memory):
                 if dep_mod.state in ('unknown','uninstalled'):
                     unmet_packages.append(dep_mod.name)
         if len(unmet_packages):
-            raise osv.except_osv(_('Unmet dependency !'), _('Following modules are uninstalled or unknown. \n\n'+'\n'.join(unmet_packages)))
+            raise osv.except_osv(_('Unmet dependency !'), _('Following modules are not installed or unknown: %s') % ('\n\n' + '\n'.join(unmet_packages)))
         mod_obj.download(cr, uid, ids, context=context)
         cr.commit()
         _, pool = pooler.restart_pool(cr.dbname, update_module=True)