diff --git a/test/persistence.test.js b/test/persistence.test.js
index ecbc4dd..4022869 100755
--- a/test/persistence.test.js
+++ b/test/persistence.test.js
@@ -67,6 +67,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       treatedData.sort(function (a, b) { return a._id - b._id })
       treatedData.length.should.equal(3)
@@ -135,6 +136,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       treatedData.sort(function (a, b) { return a._id - b._id })
       treatedData.length.should.equal(2)
@@ -168,6 +170,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       treatedData.sort(function (a, b) { return a._id - b._id })
       treatedData.length.should.equal(2)
@@ -203,6 +206,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       treatedData.sort(function (a, b) { return a._id - b._id })
       treatedData.length.should.equal(2)
@@ -236,6 +240,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       treatedData.sort(function (a, b) { return a._id - b._id })
       treatedData.length.should.equal(2)
@@ -273,6 +278,7 @@ describe('Persistence', function () {
     stream.push(null)
 
     d.persistence.treatRawStream(stream, function (err, result) {
+      assert.isNull(err)
       const treatedData = result.data
       const indexes = result.indexes
       Object.keys(indexes).length.should.equal(1)