diff --git a/package.json b/package.json
index 13ad268d9d..c6437d7384 100644
--- a/package.json
+++ b/package.json
@@ -198,12 +198,12 @@
     "test": "jest && eslint '**/*.{js,ts,tsx}' && prettier -c \"**/*.{yml,yaml}\"",
     "prebrowser-test": "npm run build",
     "browser-test": "start-server-and-test browser-test-server 4001 browser-test-tests",
-    "browser-test-server": "cross-env NODE_ENV=production PORT=4001 node server.js",
+    "browser-test-server": "cross-env NODE_ENV=production WEB_CONCURRENCY=1 PORT=4001 node server.js",
     "browser-test-tests": "cross-env BROWSER=1 jest tests/browser/browser.js",
     "sync-search": "start-server-and-test sync-search-server 4002 sync-search-indices",
     "sync-search-ghes-release": "GHES_RELEASE=1 start-server-and-test sync-search-server 4002 sync-search-indices",
     "sync-search-dry-run": "DRY_RUN=1 npm run sync-search",
-    "sync-search-server": "cross-env NODE_ENV=production PORT=4002 node server.js",
+    "sync-search-server": "cross-env NODE_ENV=production WEB_CONCURRENCY=1 PORT=4002 node server.js",
     "sync-search-indices": "script/sync-search-indices.js",
     "test-watch": "jest --watch --notify --notifyMode=change --coverage",
     "prevent-pushes-to-main": "node script/prevent-pushes-to-main.js",