diff --git a/packages/html-parser/src/index.ts b/packages/html-parser/src/index.ts
index c9240cd7..33b02022 100644
--- a/packages/html-parser/src/index.ts
+++ b/packages/html-parser/src/index.ts
@@ -116,7 +116,7 @@ export class HtmlMessageEntityParser implements IMessageEntityParser {
                         }
                         break
                     case 'a': {
-                        const url = attribs.href
+                        let url = attribs.href
                         if (!url) return
 
                         const mention = MENTION_REGEX.exec(url)
@@ -142,6 +142,8 @@ export class HtmlMessageEntityParser implements IMessageEntityParser {
                                 }
                             }
                         } else {
+                            if (url.match(/^\/\//)) url = 'http:' + url
+
                             entity = {
                                 _: 'messageEntityTextUrl',
                                 offset: plainText.length,
diff --git a/packages/markdown-parser/src/index.ts b/packages/markdown-parser/src/index.ts
index 70161515..edcef7ea 100644
--- a/packages/markdown-parser/src/index.ts
+++ b/packages/markdown-parser/src/index.ts
@@ -139,6 +139,8 @@ export class MarkdownMessageEntityParser implements IMessageEntityParser {
                             ;(ent as tl.Mutable<tl.RawMessageEntityMentionName>).userId = userId
                         }
                     } else {
+                        if (url.match(/^\/\//)) url = 'http:' + url
+
                         ;(ent as tl.Mutable<tl.RawMessageEntityTextUrl>)._ =
                             'messageEntityTextUrl'
                         ;(ent as tl.Mutable<tl.RawMessageEntityTextUrl>).url = url