diff --git a/unix/uxpty.c b/unix/uxpty.c
index 2533d958..2e1e12cb 100644
--- a/unix/uxpty.c
+++ b/unix/uxpty.c
@@ -25,6 +25,7 @@
 
 #include "putty.h"
 #include "ssh.h"
+#include "sshserver.h" /* to check the prototypes of server-needed things */
 #include "tree234.h"
 
 #ifndef OMIT_UTMP