diff --git a/src/typval.c b/src/typval.c
index 5a62fa0..cdb6175 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -2082,6 +2082,7 @@
 
 	rettv->v_type = VAR_STRING;
 	rettv->vval.v_string = string;
+	rettv->v_lock = 0;
     }
 
     return OK;