diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
index 812dbf0..fbc11a3 100644
--- a/lib/kernel_lock.c
+++ b/lib/kernel_lock.c
@@ -8,6 +8,7 @@
 #include <linux/smp_lock.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
+#include <asm/semaphore.h>
 
 /*
  * The 'big kernel semaphore'