diff --git a/ldap.c b/ldap.c
index 713eba23d..71eb50b9d 100644
--- a/ldap.c
+++ b/ldap.c
@@ -89,6 +89,10 @@ __unused static const char rcsid[] = "$Sudo$";
 # define LDAP_OPT_SUCCESS LDAP_SUCCESS
 #endif
 
+#ifndef LDAPS_PORT
+# define LDAPS_PORT 636
+#endif
+
 #if defined(HAVE_LDAP_SASL_INTERACTIVE_BIND_S) && !defined(LDAP_SASL_QUIET)
 # define LDAP_SASL_QUIET	0
 #endif