diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 7d51dd7..37cfe77 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -495,6 +495,7 @@
 {
 }
 
+#ifdef CONFIG_SMP
 void alternatives_smp_module_add(struct module *mod, char *name,
 				 void *locks, void *locks_end,
 				 void *text,  void *text_end)
@@ -504,3 +505,4 @@
 void alternatives_smp_module_del(struct module *mod)
 {
 }
+#endif