diff --git a/python/_set.py b/python/_set.py
index 934f4c27..99ebbec5 100644
--- a/python/_set.py
+++ b/python/_set.py
@@ -95,4 +95,4 @@ class set:
         return '{'+ ', '.join([repr(i) for i in self._a.keys()]) + '}'
     
     def __iter__(self):
-        return self._a.keys()
\ No newline at end of file
+        return iter(self._a.keys())
\ No newline at end of file
diff --git a/src/pocketpy.h b/src/pocketpy.h
index 2a2d6471..ed958a60 100644
--- a/src/pocketpy.h
+++ b/src/pocketpy.h
@@ -897,7 +897,7 @@ inline void init_builtins(VM* _vm) {
         for(auto& item : self.items()){
             if(!first) ss << ", ";
             first = false;
-            Str key = CAST(Str&, item.first);
+            Str key = CAST(Str&, item.first).escape();
             Str value = CAST(Str&, vm->py_json(item.second));
             ss << key << ": " << value;
         }