diff --git a/pegged/peg.d b/pegged/peg.d
index 3706ede..46b2236 100644
--- a/pegged/peg.d
+++ b/pegged/peg.d
@@ -348,7 +348,7 @@ struct ParseTree
       return children[index];
     }
 
-    ref ParseTree[] opIndex() {
+    ref ParseTree[] opIndex() return {
         return children;
     }