diff --git a/rules/modules/system.eval.inc b/rules/modules/system.eval.inc
index 70a5f51..5e37cf7 100644
--- a/rules/modules/system.eval.inc
+++ b/rules/modules/system.eval.inc
@@ -180,6 +180,7 @@ class RulesTokenEvaluator extends RulesDataInputEvaluator {
       else {
         $replacements += token_generate($var_name, $tokens, array(), $options);
       }
+      $replacements += array_fill_keys($tokens, '');
     }
 
     // Optionally clean the list of replacement values.