diff --git a/basis/locals/parser/parser.factor b/basis/locals/parser/parser.factor
index ea1a07478f..e59b6a8fc5 100644
--- a/basis/locals/parser/parser.factor
+++ b/basis/locals/parser/parser.factor
@@ -11,8 +11,13 @@ SYMBOL: in-lambda?
 : ?rewrite-closures ( form -- form' )
     in-lambda? get [ 1array ] [ rewrite-closures ] if ;
 
+ERROR: invalid-local-name name ;
+
+: check-local-name ( name -- name )
+    dup { "]" "]!" } member? [ invalid-local-name ] when ;
+
 : make-local ( name -- word )
-    "!" ?tail [
+    check-local-name "!" ?tail [
         <local-reader>
         dup <local-writer> dup name>> ,,
     ] [ <local> ] if