diff --git a/docs/KNOWN_BUGS b/docs/KNOWN_BUGS
index ae1f96bbe4..dd731b9da2 100644
--- a/docs/KNOWN_BUGS
+++ b/docs/KNOWN_BUGS
@@ -13,6 +13,7 @@ problems may have been fixed or changed somewhat since this was written.
 
  1. HTTP
  1.1 hyper memory-leaks
+ 1.2 hyper is slow
  1.5 Expect-100 meets 417
 
  2. TLS
@@ -116,6 +117,12 @@ problems may have been fixed or changed somewhat since this was written.
 
  https://github.com/curl/curl/issues/10803
 
+1.2 hyper is slow
+
+ When curl is built to use hyper for HTTP, it is unnecessary slow.
+
+ https://github.com/curl/curl/issues/11203
+
 1.5 Expect-100 meets 417
 
  If an upload using Expect: 100-continue receives an HTTP 417 response, it