diff --git a/README.md b/README.md
index dad8ec67e5b5358bf7ad9a0ec1fc0c627152d005..4f184f4f9685ae047846b91135a4930ff7a44832 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,6 @@ go get nhooyr.io/websocket@v0.2.0
 ## Roadmap
 
 - [ ] WebSockets over HTTP/2 [#4](https://github.com/nhooyr/websocket/issues/4)
-- [ ] Deflate extension support [#5](https://github.com/nhooyr/websocket/issues/5)
 
 ## Examples
 
@@ -89,6 +88,8 @@ c.Close(websocket.StatusNormalClosure, "")
 - net.Conn is never exposed as WebSocket over HTTP/2 will not have a net.Conn.
 - Using net/http's Client for dialing means we do not have to reinvent dialing hooks
   and configurations like other WebSocket libraries
+- We do not support the compression extension because Go's compress/flate library is very memory intensive
+  and browsers do not handle WebSocket compression intelligently. See [#5](https://github.com/nhooyr/websocket/issues/5)
 
 ## Comparison