diff --git a/telegram-bot-api/WebhookActor.cpp b/telegram-bot-api/WebhookActor.cpp
index 46898e320..fb3e78e86 100644
--- a/telegram-bot-api/WebhookActor.cpp
+++ b/telegram-bot-api/WebhookActor.cpp
@@ -552,7 +552,14 @@ td::Status WebhookActor::send_update() {
 
   td::HttpHeaderCreator hc;
   hc.init_post(url_.query_);
-  hc.add_header("Host", url_.host_);
+
+  auto hostHeaderValue = url_.host_;
+  // Append :port to the host header if a non-default port was specified.
+  if ((url_.protocol_ == td::HttpUrl::Protocol::Https && url_.port_ != 443) || (url_.protocol_ == td::HttpUrl::Protocol::Http && url_.port_ != 80)) {
+    hostHeaderValue += ":" + std::to_string(url_.port_);
+  }
+
+  hc.add_header("Host", hostHeaderValue);
   if (!url_.userinfo_.empty()) {
     hc.add_header("Authorization", PSLICE() << "Basic " << td::base64_encode(url_.userinfo_));
   }