diff --git a/INSTALL b/INSTALL
index eec2b37f..bbff1f23 100644
--- a/INSTALL
+++ b/INSTALL
@@ -12,13 +12,17 @@
 I. Upgrade Information
 ~~~~~~~~~~~~~~~~~~~~~~
 
-Differences to previous version 
+Differences to version 20.x
 
 - Starting with ngIRCd 21, the ciphers used by SSL are configurable and
   default to HIGH:!aNULL:@STRENGTH (OpenSSL) or SECURE128 (GnuTLS).
   Previous version were using the OpenSSL or GnuTLS defaults, DEFAULT
   and NORMAL respectively.
 
+- When adding GLINE's or KLINE's to ngIRCd 21 (or newer), all clients matching
+  the new mask will be KILL'ed. This was not the case with earlier versions
+  that only added the mask but didn't kill already connected users.
+
 Differences to version 19.x
 
 - Starting with ngIRCd 20, users can "cloak" their hostname only when the