diff --git a/_site/heti-addon.js b/_site/heti-addon.js
index 6aad703..1ab17f4 100644
--- a/_site/heti-addon.js
+++ b/_site/heti-addon.js
@@ -688,6 +688,13 @@
 
 	class Heti {
 	  constructor (rootSelector) {
+	    try {
+	      new RegExp(`(?<=\d)\d`, 'g').test('');
+	    } catch (err) {
+	      console.warn(err.name, '浏览器尚未实现 RegExp positive lookbehind');
+	      return
+	    }
+
 	    this.rootSelector = rootSelector || '.heti';
 	    this.REG_FULL = new RegExp(`(?<=[${CJK}])( *[${ANS}]+(?: +[${ANS}]+)* *)(?=[${CJK}])`, 'g');
 	    this.REG_START = new RegExp(`([${ANS}]+(?: +[${ANS}]+)* *)(?=[${CJK}])`, 'g');
diff --git a/js/heti-addon.js b/js/heti-addon.js
index 5a00551..f8d1113 100644
--- a/js/heti-addon.js
+++ b/js/heti-addon.js
@@ -44,6 +44,13 @@ const hasOwn = {}.hasOwnProperty
 
 class Heti {
   constructor (rootSelector) {
+    try {
+      new RegExp(`(?<=\d)\d`, 'g').test('')
+    } catch (err) {
+      console.warn(err.name, '浏览器尚未实现 RegExp positive lookbehind')
+      return
+    }
+
     this.rootSelector = rootSelector || '.heti'
     this.REG_FULL = new RegExp(`(?<=[${CJK}])( *[${ANS}]+(?: +[${ANS}]+)* *)(?=[${CJK}])`, 'g')
     this.REG_START = new RegExp(`([${ANS}]+(?: +[${ANS}]+)* *)(?=[${CJK}])`, 'g')