1 files changed, 1 insertions, 1 deletions
diff --git a/vm_args.c b/vm_args.c
index c1d829c019..7a2f8135da 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -392,7 +392,7 @@ args_setup_kw_parameters_lookup(const ID key, VALUE *ptr, const VALUE *const pas
     return FALSE;
 }
 
-#define KW_SPECIFIED_BITS_MAX 32 /* TODO: 32 -> Fixnum's max bits */
+#define KW_SPECIFIED_BITS_MAX (32-1) /* TODO: 32 -> Fixnum's max bits */
 
 static void
 args_setup_kw_parameters(rb_execution_context_t *const ec, const rb_iseq_t *const iseq,