diff --git a/compat/imsg-buffer.c b/compat/imsg-buffer.c
index 635f19b9..74485bbd 100644
--- a/compat/imsg-buffer.c
+++ b/compat/imsg-buffer.c
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
+#include <arpa/inet.h>
 
 #include <limits.h>
 #include <errno.h>