diff --git a/runner.js b/runner.js
index 7f55154..0cdc530 100644
--- a/runner.js
+++ b/runner.js
@@ -21,7 +21,7 @@ export function runTest(job, onLine) {
       '--browser', job.browser,
       '-n', String(job.runs),
       '--outputFolder', outputFolder,
-      '--json',
+      '--plugins.add', 'analysisstorer', // not in default set — needed to write pageSummary JSON
       '--sustainable.enable',
       '--sustainable.useGreenWebHostingAPI',
       '--axe.enable',