diff --git a/src/core_plugins/timelion/public/__tests__/_tick_generator.js b/src/core_plugins/timelion/public/__tests__/_tick_generator.js
index 4827f83ff66d1..392feec8e0480 100644
--- a/src/core_plugins/timelion/public/__tests__/_tick_generator.js
+++ b/src/core_plugins/timelion/public/__tests__/_tick_generator.js
@@ -3,7 +3,7 @@ import ngMock from 'ng_mock';
 describe('Tick Generator', function () {
 
   let generateTicks;
-  let axes = [
+  const axes = [
     {
       min: 0,
       max: 5000,
diff --git a/src/core_plugins/timelion/public/panels/timechart/tick_generator.js b/src/core_plugins/timelion/public/panels/timechart/tick_generator.js
index 8ae15acfb089f..2a027d502c632 100644
--- a/src/core_plugins/timelion/public/panels/timechart/tick_generator.js
+++ b/src/core_plugins/timelion/public/panels/timechart/tick_generator.js
@@ -2,7 +2,7 @@ module.exports = function generateTicksProvider() {
 
   function floorInBase(n, base) {
     return base * Math.floor(n / base);
-  };
+  }
 
   function generateTicks(axis) {
     const returnTicks = [];
@@ -35,7 +35,7 @@ module.exports = function generateTicksProvider() {
     } while (tickVal < axis.max);
 
     return returnTicks;
-  };
+  }
 
   return function (axis) {
     return generateTicks(axis);
diff --git a/src/core_plugins/timelion/public/services/tick_formatters.js b/src/core_plugins/timelion/public/services/tick_formatters.js
index 6a3719533a5a0..2cef2bc97779e 100644
--- a/src/core_plugins/timelion/public/services/tick_formatters.js
+++ b/src/core_plugins/timelion/public/services/tick_formatters.js
@@ -1,10 +1,10 @@
 define(function (require) {
 
   return function ticketFormatters() {
-    var formatters =  {
+    const formatters =  {
       'bits': function (val, axis) {
-        var labels = ['b','kb','mb','gb','tb','pb'];
-        var index = 0;
+        const labels = ['b','kb','mb','gb','tb','pb'];
+        let index = 0;
         while (val >= 1000 && index < labels.length) {
           val /= 1000;
           index++;
@@ -12,8 +12,8 @@ define(function (require) {
         return (Math.round(val * 100) / 100) + labels[index];
       },
       'bits/s': function (val, axis) {
-        var labels = ['b/s','kb/s','mb/s','gb/s','tb/s','pb/s'];
-        var index = 0;
+        const labels = ['b/s','kb/s','mb/s','gb/s','tb/s','pb/s'];
+        let index = 0;
         while (val >= 1000 && index < labels.length) {
           val /= 1000;
           index++;
@@ -21,8 +21,8 @@ define(function (require) {
         return (Math.round(val * 100) / 100) + labels[index];
       },
       'bytes': function (val, axis) {
-        var labels = ['B','KB','MB','GB','TB','PB'];
-        var index = 0;
+        const labels = ['B','KB','MB','GB','TB','PB'];
+        let index = 0;
         while (val >= 1024 && index < labels.length) {
           val /= 1024;
           index++;
@@ -30,8 +30,8 @@ define(function (require) {
         return (Math.round(val * 100) / 100) + labels[index];
       },
       'bytes/s': function (val, axis) {
-        var labels = ['B/s','KB/s','MB/s','GB/s','TB/s','PB/s'];
-        var index = 0;
+        const labels = ['B/s','KB/s','MB/s','GB/s','TB/s','PB/s'];
+        let index = 0;
         while (val >= 1024 && index < labels.length) {
           val /= 1024;
           index++;
@@ -42,8 +42,8 @@ define(function (require) {
         return val.toLocaleString('en', { style: 'currency', currency: axis.options.units.prefix || 'USD' });
       },
       'custom': function (val, axis) {
-        var prefix = axis.options.units.prefix;
-        var suffix = axis.options.units.suffix;
+        const prefix = axis.options.units.prefix;
+        const suffix = axis.options.units.suffix;
         return prefix + val + suffix;
       }
     };
diff --git a/src/core_plugins/timelion/server/series_functions/yaxis.js b/src/core_plugins/timelion/server/series_functions/yaxis.js
index 54d5e77948b29..306195cac6da3 100644
--- a/src/core_plugins/timelion/server/series_functions/yaxis.js
+++ b/src/core_plugins/timelion/server/series_functions/yaxis.js
@@ -73,7 +73,7 @@ module.exports = new Chainable('yaxis', {
       myAxis.axisLabelUseCanvas = true;
 
       if (units) {
-        var unitTokens = units.split(':');
+        const unitTokens = units.split(':');
         if (!tickFormatters[unitTokens[0]]) {
           throw new Error (`${units} is not a supported unit type.`);
         }