diff --git a/Query.php b/Query.php
index b73ff79..f974b3d 100644
--- a/Query.php
+++ b/Query.php
@@ -541,7 +541,7 @@ class Query extends Component implements QueryInterface
      */
     protected function buildSelect($columns, &$params)
     {
-        if ($columns == null || empty($columns)) {
+        if ($columns === null || empty($columns)) {
             return 'RETURN ' . $this->from;
         }