diff --git a/src/extension.ts b/src/extension.ts
index e79a732b0b2ff6c84357a2db93f90e85e4e3699b..0e7d70b9c319b92521ed2e4100c03d73653bde39 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -499,7 +499,15 @@       createCompletionItemProvider({
         items: this._items,
         languages: ['vue'],
         regex: /\bclass=["']([^"']*)$/,
-        enable: isWithinTemplate,
+        enable: text => {
+          if (
+            text.indexOf('<template') !== -1 &&
+            text.indexOf('</template>') === -1
+          ) {
+            return true
+          }
+          return false
+        },
         triggerCharacters: ["'", '"', ' ', separator]
           .concat([
             Object.keys(
@@ -780,13 +788,3 @@     },
     ' '
   )
 }
-
-function isWithinTemplate(text: string) {
-  let regex = /(<\/?template\b)/g
-  let match
-  let d = 0
-  while ((match = regex.exec(text)) !== null) {
-    d += match[0] === '</template' ? -1 : 1
-  }
-  return d !== 0
-}