diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index 6d9318e1c3d4..4bafa370e163 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -63,6 +63,7 @@
 #include <net/bpf.h>
 #endif
 
+#include <net/if_tunvar.h>
 #include <net/if_tun.h>
 
 static void tunattach __P((void *));