diff --git a/NEWS.md b/NEWS.md
index d70517d05..aebc2a506 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -16,6 +16,8 @@
 
 * Fixed a bug in `onBookmark` hook that caused elements to not be excluded from URL bookmarking. (#3762)
 
+* Fixed a bug with stack trace capturing that caused reactives with very long async promise chains (hundreds/thousands of steps) to become extremely slow. Chains this long are unlikely to be written by hand, but {coro} async generators and {elmer} async streaming were easily creating problematically long chains. (#4155)
+
 # shiny 1.9.1
 
 ## Bug fixes