diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index f8b2184a1ce..c7651c98ab5 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -25,6 +25,7 @@
 #include <signal.h>
 #include <fcntl.h>
 #include <ctype.h>
+#include <limits.h>
 
 #include "libpq-fe.h"
 #include "fe-auth.h"