diff --git a/src/main/kotlin/dev/usbharu/hideout/plugins/ActivityPub.kt b/src/main/kotlin/dev/usbharu/hideout/plugins/ActivityPub.kt
index 6ed1783d..c76d52e0 100644
--- a/src/main/kotlin/dev/usbharu/hideout/plugins/ActivityPub.kt
+++ b/src/main/kotlin/dev/usbharu/hideout/plugins/ActivityPub.kt
@@ -63,7 +63,7 @@ val httpSignaturePlugin = createClientPlugin("HttpSign", ::HttpSignaturePluginCo
 
 
         request.header("Date", format.format(Date()))
-        request.header("Host",request.url.host+request.url.port.toString())
+        request.header("Host", "${request.url.host}")
         println(request.bodyType)
         println(request.bodyType?.type)
         if (request.bodyType?.type == String::class) {