diff --git a/src/parser/index.js b/src/parser/index.js
index 1a0227fd4e..1440ea1a41 100644
--- a/src/parser/index.js
+++ b/src/parser/index.js
@@ -41,10 +41,12 @@ export default class Parser extends Tokenizer {
     }
 
     for (let name of plugins) {
-      pluginMap[name] = true;
+      if (!pluginMap[name]) {
+        pluginMap[name] = true;
 
-      let plugin = exports.plugins[name];
-      if (plugin) plugin(this);
+        let plugin = exports.plugins[name];
+        if (plugin) plugin(this);
+      }
     }
 
     return pluginMap;