1 files changed, 1 insertions, 1 deletions
diff --git a/src/Components/SetOperation.php b/src/Components/SetOperation.php
index 2d76704..eef0f80 100644
--- a/src/Components/SetOperation.php
+++ b/src/Components/SetOperation.php
@@ -122,7 +122,7 @@ class SetOperation extends Component
                         'breakOnAlias' => true,
                     ]
                 );
-                if (is_null($tmp)) {
+                if ($tmp === null) {
                     $parser->error('Missing expression.', $token);
                     break;
                 }