diff --git a/src/obj/map.rs b/src/obj/map.rs
index a4cf943..4bb6dc8 100644
--- a/src/obj/map.rs
+++ b/src/obj/map.rs
@@ -135,7 +135,7 @@ impl Map {
         let this_borrowed = this.borrow();
         let map_obj = this_borrowed.as_any().downcast_ref::<Map>().unwrap();
         if map_obj.table().len() == 0 {
-            return Str::create("[]");
+            return Str::create("[:]");
         }
 
         let mut repr = "[".to_string();