diff --git a/arch/x86/core/intel64/locore.S b/arch/x86/core/intel64/locore.S
index 19eab541e74..57a97088075 100644
--- a/arch/x86/core/intel64/locore.S
+++ b/arch/x86/core/intel64/locore.S
@@ -14,7 +14,7 @@
 .section .locore,"ax"
 .code32
 
-#ifdef CONFIG_SMP && (CONFIG_MP_NUM_CPUS > 1)
+#if defined(CONFIG_SMP) && (CONFIG_MP_NUM_CPUS > 1)
 
 	/*
 	 * APs are sent here on startup, in real mode. This