diff --git a/mollom.admin.inc b/mollom.admin.inc
index 4f2c522..103250b 100644
--- a/mollom.admin.inc
+++ b/mollom.admin.inc
@@ -48,7 +48,7 @@ function _mollom_supported_languages() {
     }
     if ($found) {
       // Update the list of installed languages that are supported.
-      if (isset($languages_enabled[$langcode])) {
+      if (isset($languages_enabled[$langcode]) && isset($simplified_code) && isset($supported)) {
         $installed_languages[$supported[$simplified_code]] = $simplified_code;
       }
     }