diff --git a/src/renderer/plugins/markdown-link.ts b/src/renderer/plugins/markdown-link.ts
index a274f5afe..7535f900a 100644
--- a/src/renderer/plugins/markdown-link.ts
+++ b/src/renderer/plugins/markdown-link.ts
@@ -199,7 +199,7 @@ function convertLink (state: StateCore) {
       return
     }
 
-    if (/^[a-zA-Z+]+:/.test(attrVal)) { // xxx:
+    if (/^[a-zA-Z+_-]+:/.test(attrVal)) { // xxx:
       return
     }