diff --git a/i18n_string/i18n_string.inc b/i18n_string/i18n_string.inc
index 49e750b..bfffa7f 100644
--- a/i18n_string/i18n_string.inc
+++ b/i18n_string/i18n_string.inc
@@ -374,7 +374,7 @@ class i18n_string_textgroup_default {
 
     $cache_data = array();
     foreach ($this->cache_multiple as $pattern => $strings) {
-      foreach ($this->strings as $context => $i18n_string_object) {
+      foreach ($strings as $context => $i18n_string_object) {
         $cache_data[$pattern][$context] = $context;
       }
     }