diff --git a/Misc/NEWS b/Misc/NEWS
index 36567f7..49a3885 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -166,6 +166,9 @@
 Library
 -------
 
+- Issue #5401: Fixed a performance problem in mimetypes when ``from mimetypes
+  import guess_extension`` was used.
+
 - Issue #1733986: Fixed mmap crash in accessing elements of second map object
   with same tagname but larger size than first map. (Windows)