diff --git a/kprobe_queue.c b/kprobe_queue.c
index 49c52f8..789dcf8 100644
--- a/kprobe_queue.c
+++ b/kprobe_queue.c
@@ -22,6 +22,7 @@
 #include <string.h>
 #include <strings.h>
 #include <time.h>
+#include <unistd.h>
 
 #include "quark.h"