diff --git a/src/client/updaters/attribute.js b/src/client/updaters/attribute.js
index a06df9d..e3cf648 100644
--- a/src/client/updaters/attribute.js
+++ b/src/client/updaters/attribute.js
@@ -14,7 +14,7 @@ export default function updateAttribute({ attribute } = {}, attrs, tag) {
       const val = attrs[attr] || ''
       tag.setAttribute(attr, val)
 
-      if (vueMetaAttrs.indexOf(attr) === -1) {
+      if (!vueMetaAttrs.includes(attr)) {
         vueMetaAttrs.push(attr)
       }
 
diff --git a/src/client/updaters/tag.js b/src/client/updaters/tag.js
index 05aa85f..df3c044 100644
--- a/src/client/updaters/tag.js
+++ b/src/client/updaters/tag.js
@@ -44,7 +44,7 @@ export default function updateTag({ attribute, tagIDKeyName } = {}, type, tags,
             } else {
               newElement.appendChild(document.createTextNode(tag.cssText))
             }
-          } else if ([tagIDKeyName, 'body'].indexOf(attr) !== -1) {
+          } else if ([tagIDKeyName, 'body'].includes(attr)) {
             const _attr = `data-${attr}`
             const value = (typeof tag[attr] === 'undefined') ? '' : tag[attr]
             newElement.setAttribute(_attr, value)
diff --git a/src/shared/getMetaInfo.js b/src/shared/getMetaInfo.js
index 8617037..14ff7ba 100644
--- a/src/shared/getMetaInfo.js
+++ b/src/shared/getMetaInfo.js
@@ -122,11 +122,11 @@ export default function getMetaInfo({ keyName, tagIDKeyName, metaTemplateKeyName
 
   // sanitizes potentially dangerous characters
   const escape = info => Object.keys(info).reduce((escaped, key) => {
-    let isDisabled = ref && ref.indexOf(key) > -1
+    let isDisabled = ref && ref.includesOf(key)
     const tagID = info[tagIDKeyName]
 
     if (!isDisabled && tagID) {
-      isDisabled = refByTagID && refByTagID[tagID] && refByTagID[tagID].indexOf(key) > -1
+      isDisabled = refByTagID && refByTagID[tagID] && refByTagID[tagID].includes(key)
     }
 
     const val = info[key]