diff --git a/imap-send.c b/imap-send.c
index 203284d8f0..1b38b3af67 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -28,6 +28,7 @@
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
+#include <sys/socket.h>
 #include <netdb.h>
 
 typedef struct store_conf {