diff --git a/UPGRADE.txt b/UPGRADE.txt
index 408a3fae90..8081f39370 100644
--- a/UPGRADE.txt
+++ b/UPGRADE.txt
@@ -26,6 +26,7 @@ from 1.8.23.0 to 1.8.24.0:
 * The option "register_retry_403" has been added to chan_sip to work around
   servers that are known to erroneously send 403 in response to valid
   REGISTER requests and allows Asterisk to continue attepmting to connect.
+  Due to a failed merge, this option is present, but non-functional until 1.8.26.0.
 
 * Certain dialplan functions have been marked as 'dangerous', and may only be
   executed from the dialplan. Execution from extenal sources (AMI's GetVar and