diff --git a/src/typval.c b/src/typval.c
index 1db0d77..5151f72 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -177,7 +177,7 @@
     switch (varp->v_type)
     {
 	case VAR_NUMBER:
-	    if (want_bool && varp->vval.v_number != 0
+	    if (in_vim9script() && want_bool && varp->vval.v_number != 0
 						   && varp->vval.v_number != 1)
 	    {
 		semsg(_(e_using_number_as_bool_nr), varp->vval.v_number);