diff --git a/mm/usercopy.c b/mm/usercopy.c
index b3de3c4eefba..540968b481e7 100644
--- a/mm/usercopy.c
+++ b/mm/usercopy.c
@@ -294,7 +294,10 @@ static bool enable_checks __initdata = true;
 
 static int __init parse_hardened_usercopy(char *str)
 {
-	return strtobool(str, &enable_checks);
+	if (strtobool(str, &enable_checks))
+		pr_warn("Invalid option string for hardened_usercopy: '%s'\n",
+			str);
+	return 1;
 }
 
 __setup("hardened_usercopy=", parse_hardened_usercopy);