diff --git a/bin/RepoBot.js b/bin/RepoBot.js
index da0ae37..e56dcdf 100644
--- a/bin/RepoBot.js
+++ b/bin/RepoBot.js
@@ -24,9 +24,10 @@ class RepoBot {
       templates
     } = options || {};
 
-    this.templates = Object.assign({
-      published: NOTIFY_PR_TEMPLATE
-    }, templates);
+    this.templates = {
+      published: NOTIFY_PR_TEMPLATE,
+      ...templates
+    };
 
     this.github = api || new GithubAPI(owner, repo);
 
diff --git a/lib/core/mergeConfig.js b/lib/core/mergeConfig.js
index c510073..4430546 100644
--- a/lib/core/mergeConfig.js
+++ b/lib/core/mergeConfig.js
@@ -96,7 +96,7 @@ export default function mergeConfig(config1, config2) {
     headers: (a, b , prop) => mergeDeepProperties(headersToObject(a), headersToObject(b),prop, true)
   };
 
-  utils.forEach(Object.keys(Object.assign({}, config1, config2)), function computeConfigValue(prop) {
+  utils.forEach(Object.keys({...config1, ...config2}), function computeConfigValue(prop) {
     const merge = mergeMap[prop] || mergeDeepProperties;
     const configValue = merge(config1[prop], config2[prop], prop);
     (utils.isUndefined(configValue) && merge !== mergeDirectKeys) || (config[prop] = configValue);
diff --git a/lib/helpers/toURLEncodedForm.js b/lib/helpers/toURLEncodedForm.js
index 988a38a..ffa95ec 100644
--- a/lib/helpers/toURLEncodedForm.js
+++ b/lib/helpers/toURLEncodedForm.js
@@ -5,7 +5,7 @@ import toFormData from './toFormData.js';
 import platform from '../platform/index.js';
 
 export default function toURLEncodedForm(data, options) {
-  return toFormData(data, new platform.classes.URLSearchParams(), Object.assign({
+  return toFormData(data, new platform.classes.URLSearchParams(), {
     visitor: function(value, key, path, helpers) {
       if (platform.isNode && utils.isBuffer(value)) {
         this.append(key, value.toString('base64'));
@@ -13,6 +13,7 @@ export default function toURLEncodedForm(data, options) {
       }
 
       return helpers.defaultVisitor.apply(this, arguments);
-    }
-  }, options));
+    },
+    ...options
+  });
 }