diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 55fee12cea6defc065d76841bef48fcd442058eb..e29a6c9bba005ecc8fc242c5adbdc3c9e70b78c3 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -38,6 +38,7 @@
 #define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
 
 #else /* ! CONFIG_SMP */
+#define LOCK_PREFIX_HERE ""
 #define LOCK_PREFIX ""
 #endif