diff --git a/data_link.cpp b/data_link.cpp
index 9a4a12e..27cda23 100644
--- a/data_link.cpp
+++ b/data_link.cpp
@@ -1,4 +1,5 @@
 #include "data_link.h"
+#include <cstring>
 #include <pcap.h>
 
 int datalink2off(int dl_id)