diff --git a/tests/PHPStan/SarifErrorFormatter.php b/tests/PHPStan/SarifErrorFormatter.php
index 92c0255cc..ce8b7f869 100644
--- a/tests/PHPStan/SarifErrorFormatter.php
+++ b/tests/PHPStan/SarifErrorFormatter.php
@@ -64,7 +64,7 @@ public function formatErrors(AnalysisResult $analysisResult, Output $output): in
                                 'uriBaseId' => self::URI_BASE_ID,
                             ],
                             'region' => [
-                                'startLine' => $fileSpecificError->getLine(),
+                                'startLine' => (int) $fileSpecificError->getLine(),
                             ],
                         ],
                     ],