diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
index 6d8772339d76..3f15aaf54855 100644
--- a/arch/s390/lib/uaccess_mvcos.c
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -162,6 +162,7 @@ static size_t clear_user_mvcos(size_t size, void __user *to)
 	return size;
 }
 
+#ifdef CONFIG_S390_SWITCH_AMODE
 static size_t strnlen_user_mvcos(size_t count, const char __user *src)
 {
 	char buf[256];
@@ -199,6 +200,7 @@ static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
 	} while ((len_str == len) && (done < count));
 	return done;
 }
+#endif /* CONFIG_S390_SWITCH_AMODE */
 
 struct uaccess_ops uaccess_mvcos = {
 	.copy_from_user = copy_from_user_mvcos_check,