diff --git a/src/testing.c b/src/testing.c
index 80596d4..42030d7 100644
--- a/src/testing.c
+++ b/src/testing.c
@@ -340,10 +340,14 @@
     static int
 assert_beeps(typval_T *argvars, int no_beep)
 {
-    char_u	*cmd = tv_get_string_chk(&argvars[0]);
+    char_u	*cmd;
     garray_T	ga;
     int		ret = 0;
 
+    if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
+	return 0;
+
+    cmd = tv_get_string_chk(&argvars[0]);
     called_vim_beep = FALSE;
     suppress_errthrow = TRUE;
     emsg_silent = FALSE;
@@ -367,7 +371,7 @@
 }
 
 /*
- * "assert_beeps(cmd [, error])" function
+ * "assert_beeps(cmd)" function
  */
     void
 f_assert_beeps(typval_T *argvars, typval_T *rettv)
@@ -376,7 +380,7 @@
 }
 
 /*
- * "assert_nobeep(cmd [, error])" function
+ * "assert_nobeep(cmd)" function
  */
     void
 f_assert_nobeep(typval_T *argvars, typval_T *rettv)
@@ -947,6 +951,11 @@
     int     val;
     static int save_starting = -1;
 
+    if (in_vim9script()
+	    && (check_for_string_arg(argvars, 0) == FAIL
+		|| check_for_number_arg(argvars, 1) == FAIL))
+	return;
+
     if (argvars[0].v_type != VAR_STRING
 	    || (argvars[1].v_type) != VAR_NUMBER)
 	emsg(_(e_invarg));