1 files changed, 3 insertions, 1 deletions
diff --git a/class.c b/class.c
index 43123f1b3f..3ebff44d55 100644
--- a/class.c
+++ b/class.c
@@ -1881,10 +1881,12 @@ NORETURN(static void unknown_keyword_error(VALUE hash, const ID *table, int keyw
 static void
 unknown_keyword_error(VALUE hash, const ID *table, int keywords)
 {
+    st_table *tbl = rb_hash_tbl_raw(hash);
     VALUE keys;
     int i;
     for (i = 0; i < keywords; i++) {
-	rb_hash_delete(hash, ID2SYM(table[i]));
+	st_data_t key = ID2SYM(table[i]);
+	st_delete(tbl, &key, NULL);
     }
     keys = rb_funcall(hash, rb_intern("keys"), 0, 0);
     if (!RB_TYPE_P(keys, T_ARRAY)) rb_raise(rb_eArgError, "unknown keyword");