--- a/programs/pluto/connections.c
+++ b/programs/pluto/connections.c
@@ -35,6 +35,7 @@
 #include <stdio.h>
 #include <stddef.h>
 #include <stdlib.h>
+#include <limits.h>
 #include <unistd.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
--- a/programs/pluto/rcv_whack.c
+++ b/programs/pluto/rcv_whack.c
@@ -36,6 +36,7 @@
 #include <resolv.h>
 #include <fcntl.h>
 #include <unistd.h>		/* for gethostname() */
+#include <limits.h>
 
 #include <event2/event.h>
 #include <event2/event_struct.h>