diff --git a/libc/netbsd/resolv/res_cache.c b/libc/netbsd/resolv/res_cache.c
index e88c221..24edbb6 100644
--- a/libc/netbsd/resolv/res_cache.c
+++ b/libc/netbsd/resolv/res_cache.c
@@ -42,6 +42,7 @@
 
 #include <arpa/inet.h>
 #include "resolv_private.h"
+#include "resolv_iface.h"
 
 /* This code implements a small and *simple* DNS resolver cache.
  *