diff --git a/src/builtins.h b/src/builtins.h
index 01115f9d..38aed671 100644
--- a/src/builtins.h
+++ b/src/builtins.h
@@ -406,8 +406,8 @@ class set:
     def __repr__(self):
         if len(self) == 0:
             return 'set()'
-        return '{'+ ', '.join(self._a.keys()) + '}'
-    
+        return '{'+ ', '.join([repr(i) for i in self._a.keys()]) + '}'
+
     def __iter__(self):
         return self._a.keys()
 )";