diff --git a/src/libcharon/plugins/duplicheck/duplicheck.c b/src/libcharon/plugins/duplicheck/duplicheck.c
index 508e8e386..7c4cd5ce1 100644
--- a/src/libcharon/plugins/duplicheck/duplicheck.c
+++ b/src/libcharon/plugins/duplicheck/duplicheck.c
@@ -19,8 +19,10 @@
 #include <stdlib.h>
 #include <stddef.h>
 #include <stdio.h>
+#include <string.h>
 #include <errno.h>
 #include <arpa/inet.h>
+#include <netinet/in.h>
 
 #include "duplicheck_msg.h"