diff --git a/config/karma/expectation-chrome-canary.js b/config/karma/expectation-chrome-canary.js
index 40c73c5b8..f8e2bfca1 100644
--- a/config/karma/expectation-chrome-canary.js
+++ b/config/karma/expectation-chrome-canary.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-chrome.js b/config/karma/expectation-chrome.js
index 23ce1eb28..240bd550e 100644
--- a/config/karma/expectation-chrome.js
+++ b/config/karma/expectation-chrome.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-edge.js b/config/karma/expectation-edge.js
index 9b9e20aee..7068f38a2 100644
--- a/config/karma/expectation-edge.js
+++ b/config/karma/expectation-edge.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-firefox-developer.js b/config/karma/expectation-firefox-developer.js
index 3205d573d..594dedab9 100644
--- a/config/karma/expectation-firefox-developer.js
+++ b/config/karma/expectation-firefox-developer.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-firefox.js b/config/karma/expectation-firefox.js
index 1ba73d33c..58011f685 100644
--- a/config/karma/expectation-firefox.js
+++ b/config/karma/expectation-firefox.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-opera.js b/config/karma/expectation-opera.js
index c8961e747..0cc13e46a 100644
--- a/config/karma/expectation-opera.js
+++ b/config/karma/expectation-opera.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {
 
diff --git a/config/karma/expectation-safari.js b/config/karma/expectation-safari.js
index 767e99085..ce5e9adba 100644
--- a/config/karma/expectation-safari.js
+++ b/config/karma/expectation-safari.js
@@ -1,4 +1,4 @@
-var common = require('./expectation.js');
+const common = require('./expectation.js');
 
 module.exports = (config) => {