diff --git a/src/stub.js b/src/stub.js
index ee342b5e3d..b5dd0d85a0 100644
--- a/src/stub.js
+++ b/src/stub.js
@@ -5,7 +5,7 @@ import * as builtIns from "builtInLanguages";
 const hljs = HighlightJS;
 
 for (const key of Object.keys(builtIns)) {
-  const languageName = key.replace("grmr_", "");
+  const languageName = key.replace("grmr_", "").replace("_", "-");
   hljs.registerLanguage(languageName, builtIns[key]);
 }
 // console.log(hljs.listLanguages());