diff --git a/ext/ldap/ldap.c b/ext/ldap/ldap.c
index 119e942d5a4..265b03ced8b 100644
--- a/ext/ldap/ldap.c
+++ b/ext/ldap/ldap.c
@@ -2017,7 +2017,7 @@ PHP_FUNCTION(ldap_start_tls)
 {
 	zval **link;
 	ldap_linkdata *ld;
-	int rc;
+	int rc, protocol = LDAP_VERSION3;
 
 	if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &link) == FAILURE) {
 		WRONG_PARAM_COUNT;
@@ -2025,7 +2025,9 @@ PHP_FUNCTION(ldap_start_tls)
 
 	ZEND_FETCH_RESOURCE(ld, ldap_linkdata *, link, -1, "ldap link", le_link);
 
-	if ((rc = ldap_start_tls_s(ld->link, NULL, NULL)) != LDAP_SUCCESS) {
+	if (((rc = ldap_set_option(ld->link, LDAP_OPT_PROTOCOL_VERSION, &protocol)) != LDAP_SUCCESS) ||
+		((rc = ldap_start_tls_s(ld->link, NULL, NULL)) != LDAP_SUCCESS)
+	) {
 		php_error_docref(NULL TSRMLS_CC, E_WARNING,"Unable to start TLS: %s", ldap_err2string(rc));
 		RETURN_FALSE;
 	} else {