diff --git a/.eslintrc.yaml b/.eslintrc.yaml
index 1d2b8ec67..a13d74756 100644
--- a/.eslintrc.yaml
+++ b/.eslintrc.yaml
@@ -2,7 +2,6 @@
 extends: "@elastic/eslint-config-kibana"
 
 rules:
-  no-var: warn
   no-unused-vars: warn
   semi: warn
   one-var: warn
diff --git a/grunt/utils.js b/grunt/utils.js
index 32b4b88dc..8a05e1473 100644
--- a/grunt/utils.js
+++ b/grunt/utils.js
@@ -6,7 +6,7 @@ const stable = pkg.config.supported_es_branches;
 const unstable = pkg.config.unstable_es_branches;
 const branches = [].concat(stable, unstable);
 
-var utils = {
+const utils = {
   branchSuffix: function (branch) {
     return branch === utils.branches._default ? '' : '_' + _.snakeCase(branch);
   },
diff --git a/src/lib/client_action.js b/src/lib/client_action.js
index 975d7bdfe..d54c1e3e8 100644
--- a/src/lib/client_action.js
+++ b/src/lib/client_action.js
@@ -327,8 +327,8 @@ function exec(transport, spec, params, cb) {
         case 'method':
           request.method = _.toUpperString(params[key]);
           break;
-        default:
-          var paramSpec = spec.params[key];
+        default: {
+          const paramSpec = spec.params[key];
           if (paramSpec) {
           // param keys don't always match the param name, in those cases it's stored in the param def as "name"
             paramSpec.name = paramSpec.name || key;
@@ -346,6 +346,7 @@ function exec(transport, spec, params, cb) {
           } else {
             query[key] = params[key];
           }
+        }
       }
     }
   }
diff --git a/src/lib/connectors/jquery.js b/src/lib/connectors/jquery.js
index a61da5c38..51b4f3cd3 100644
--- a/src/lib/connectors/jquery.js
+++ b/src/lib/connectors/jquery.js
@@ -26,7 +26,7 @@ JqueryConnector.prototype.request = function (params, cb) {
     done: cb
   };
 
-  var jqXHR = jQuery.ajax(ajax)
+  const jqXHR = jQuery.ajax(ajax)
     .done(function (data) {
       cb(null, data, jqXHR.statusCode(), {
         'content-type': jqXHR.getResponseHeader('content-type')
diff --git a/src/lib/log.js b/src/lib/log.js
index fc4f4a511..6c53c8220 100644
--- a/src/lib/log.js
+++ b/src/lib/log.js
@@ -150,11 +150,12 @@ Log.levels = [
  */
 Log.parseLevels = function (input) {
   switch (typeof input) {
-    case 'string':
-      var i = _.indexOf(Log.levels, input);
+    case 'string': {
+      const i = _.indexOf(Log.levels, input);
       if (i >= 0) {
         return Log.levels.slice(0, i + 1);
       }
+    }
     /* fall through */
     case 'object':
       if (_.isArray(input)) {
diff --git a/src/lib/transport/sniff_on_connection_fault.js b/src/lib/transport/sniff_on_connection_fault.js
index 06ce3acdd..c775ce4af 100644
--- a/src/lib/transport/sniff_on_connection_fault.js
+++ b/src/lib/transport/sniff_on_connection_fault.js
@@ -17,7 +17,7 @@ module.exports = function setupSniffOnConnectionFault(transport) {
 
   // do the actual sniff, if the sniff is unable to
   // connect to a node this function will be called again by the connectionPool
-  var work = function () {
+  const work = function () {
     work.timerId = transport._timeout(work.timerId);
     transport.sniff();
   };
diff --git a/src/lib/utils.js b/src/lib/utils.js
index e1303a5e4..02ab41293 100644
--- a/src/lib/utils.js
+++ b/src/lib/utils.js
@@ -343,8 +343,8 @@ _.funcEnum = function (config, name, opts, def) {
         return opts[val];
       }
     /* falls through */
-    default:
-      var err = 'Invalid ' + name + ' "' + val + '", expected a function';
+    default: {
+      let err = 'Invalid ' + name + ' "' + val + '", expected a function';
       switch (_.size(opts)) {
         case 0:
           break;
@@ -356,6 +356,7 @@ _.funcEnum = function (config, name, opts, def) {
           break;
       }
       throw new TypeError(err);
+    }
   }
 };
 
diff --git a/test/integration/yaml_suite/yaml_doc.js b/test/integration/yaml_suite/yaml_doc.js
index 237c08f51..2a4087966 100644
--- a/test/integration/yaml_suite/yaml_doc.js
+++ b/test/integration/yaml_suite/yaml_doc.js
@@ -403,11 +403,11 @@ YamlDoc.prototype = {
     }
 
     const client = clientManager.get();
-    var clientActionName = _.map(action.split('.'), _.camelCase).join('.');
+    const clientActionName = _.map(action.split('.'), _.camelCase).join('.');
     const clientAction = this.get(clientActionName, client);
     _.assign(inputParams, args[action]);
 
-    var params = _.transform(inputParams, _.bind(function (params, val, name) {
+    const params = _.transform(inputParams, _.bind(function (params, val, name) {
       const camelName = _.camelCase(name);
 
       // search through the params and url peices to find this param name
@@ -426,7 +426,7 @@ YamlDoc.prototype = {
       }
 
       // for ercursively traversing the params to replace '$stashed' vars
-      var transformObject = function (vals, val, i) {
+      const transformObject = function (vals, val, i) {
         if (_.isString(val)) {
           val = (val[0] === '$') ? this.get(val) : val;
         } else if (_.isPlainObject(val) || _.isArray(val)) {
diff --git a/test/mocks/browser_server.js b/test/mocks/browser_server.js
index 7e9e66ded..ba8828266 100644
--- a/test/mocks/browser_server.js
+++ b/test/mocks/browser_server.js
@@ -30,7 +30,7 @@ const server = new XhrServer(function (request) {
 
 server.start();
 
-var mockNock = module.exports = function (url) {
+const mockNock = module.exports = function (url) {
   const parsedUrl = parseUrl(url);
   const req = {
     method: 'GET',
@@ -38,7 +38,7 @@ var mockNock = module.exports = function (url) {
     times: 1
   };
 
-  var modifyReq = {
+  const modifyReq = {
     get: function (path) {
       req.path = path;
       req.method = 'GET';
diff --git a/test/unit/specs/http_connector.js b/test/unit/specs/http_connector.js
index c9b66acc3..737ed9998 100644
--- a/test/unit/specs/http_connector.js
+++ b/test/unit/specs/http_connector.js
@@ -481,12 +481,13 @@ describe('Http Connector', function () {
       const fixture = _.partial(path.join, __dirname, '../../fixtures');
       let timeout; // start the timeout once we hear back from the client
 
+      let client; // eslint-disable-line prefer-const
       const server = cp.fork(fixture('keepalive_server.js'))
         .on('message', function (port) {
           client.send(port);
         });
 
-      var client = cp.fork(fixture('keepalive.js'))
+      client = cp.fork(fixture('keepalive.js'))
         .on('message', function (output) {
           expect(output).to.have.property('remaining', 0);
           expect(output).to.have.property('timeouts', 0);
diff --git a/test/unit/specs/transport.js b/test/unit/specs/transport.js
index 11351b522..e75d224e9 100644
--- a/test/unit/specs/transport.js
+++ b/test/unit/specs/transport.js
@@ -722,6 +722,7 @@ describe('Transport Class', function () {
         });
 
         const con = getConnection(tran);
+        let ret; // eslint-disable-line prefer-const
         stub(con, 'request', function () {
           process.nextTick(function () {
             ret.abort();
@@ -731,7 +732,7 @@ describe('Transport Class', function () {
           };
         });
 
-        var ret = tran.request({});
+        ret = tran.request({});
       });
       it('ignores the response from the connection when the connector does not support aborting', function (done) {
         const tran = new Transport({