diff --git a/contrib/tcploop/tcploop.c b/contrib/tcploop/tcploop.c
index a2ab59e76..033481150 100644
--- a/contrib/tcploop/tcploop.c
+++ b/contrib/tcploop/tcploop.c
@@ -39,6 +39,7 @@
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <netdb.h>
 #include <poll.h>
 #include <signal.h>