diff --git a/lib/middlewares/operatorId.js b/lib/middlewares/operatorId.js
index 7ae838e5..baeffc22 100644
--- a/lib/middlewares/operatorId.js
+++ b/lib/middlewares/operatorId.js
@@ -19,12 +19,15 @@ function getMnemonic () {
 }
 
 function findOperatorId (req, res, next) {
-  getMnemonic().then(mnemonic => {
+  return getMnemonic().then(mnemonic => {
     return computeOperatorId(mnemonicHelpers.toEntropyBuffer(mnemonic))
   }).then(id => {
     res.locals.operatorId = id
-  }).catch(e => console.error('Error while computing operator id\n' + e))
-  next()
+    return next()
+  }).catch(e => {
+    console.error('Error while computing operator id\n' + e)
+    next(e)
+  })
 }
 
 module.exports = findOperatorId