diff --git a/scripts/test.mjs b/scripts/test.mjs
index 997b4759a..3c4d334e8 100644
--- a/scripts/test.mjs
+++ b/scripts/test.mjs
@@ -102,6 +102,7 @@ async function runTests(attempt) {
         CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS: true,
         CHROME_DEVTOOLS_MCP_CRASH_ON_UNCAUGHT: true,
         CHROME_DEVTOOLS_MCP_NO_UPDATE_CHECKS: true,
+        ...(process.env['RUNNER_DEBUG'] === '1' ? {DEBUG: 'puppeteer:*'} : {}),
       },
     });