diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index ccb01aad361..f4d8299a9c9 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -5489,6 +5489,7 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 			   *entry;
 	struct berval **values;
 	LDAP_TIMEVAL time = {PGLDAP_TIMEOUT, 0};
+	int	ldapversion = LDAP_VERSION3;
 
 	if ((url = strdup(purl)) == NULL)
 	{
@@ -5620,6 +5621,15 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 		return 3;
 	}
 
+	if ((rc = ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &ldapversion)) != LDAP_SUCCESS)
+	{
+		libpq_append_error(errorMessage, "could not set LDAP protocol version: %s",
+						   ldap_err2string(rc));
+		free(url);
+		ldap_unbind(ld);
+		return 3;
+	}
+
 	/*
 	 * Perform an explicit anonymous bind.
 	 *