diff --git a/moulinette/core.py b/moulinette/core.py
index 6bb03a1b..a002a433 100644
--- a/moulinette/core.py
+++ b/moulinette/core.py
@@ -194,7 +194,7 @@ class Translator(object):
 
         try:
             return _load_key(self.locale)
-        except KeyError:
+        except (KeyError, IndexError):
             if self.default_locale != self.locale:
                 logger.info("untranslated key '%s' for locale '%s'",
                             key, self.locale)