diff --git a/lib/middlewares/populateDeviceId.js b/lib/middlewares/populateDeviceId.js
index e406578d..e9de4d88 100644
--- a/lib/middlewares/populateDeviceId.js
+++ b/lib/middlewares/populateDeviceId.js
@@ -14,12 +14,13 @@ function sha256 (buf) {
 }
 
 const populateDeviceId = function (req, res, next) {
-  const deviceId = _.isFunction(req.connection.getPeerCertificate)
+  let deviceId = _.isFunction(req.connection.getPeerCertificate)
     ? sha256(req.connection.getPeerCertificate()?.raw)
-    : IS_STRESS_TESTING
-    ? 'placeholder' /* TODO: req... ? */
     : null
 
+  if (!deviceId && IS_STRESS_TESTING)
+    deviceId = req.headers.device_id
+
   if (!deviceId) return res.status(500).json({ error: 'Unable to find certificate' })
   req.deviceId = deviceId
   req.deviceTime = req.get('date')