diff --git a/grammar/src/expressions.grm b/grammar/src/expressions.grm
index e3160f9e295..64e454c011f 100644
--- a/grammar/src/expressions.grm
+++ b/grammar/src/expressions.grm
@@ -241,7 +241,7 @@ typeArguments
   ;
 
 valueArguments
-  : "(" (SimpleName "=")? "*"? expression{","} ")"
+  : "(" ((SimpleName "=")? "*"? expression){","} ")"
   ;
 
 jump