diff --git a/lib/treetop/compiler/node_classes/parsing_expression.rb b/lib/treetop/compiler/node_classes/parsing_expression.rb
index 2ad71e8..cc23366 100644
--- a/lib/treetop/compiler/node_classes/parsing_expression.rb
+++ b/lib/treetop/compiler/node_classes/parsing_expression.rb
@@ -79,7 +79,7 @@ def extend_result_with_inline_module
       end
     
       def reset_index
-        builder.assign 'self.index', start_index_var
+        builder.assign '@index', start_index_var
       end
       
       def epsilon_node