diff --git a/configure.ac b/configure.ac
index 9d36f9b7c..dd80a7168 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,7 @@ dnl         "Z" for unsupported trunk builds,
 dnl         "0" for stable, supported releases
 dnl these should be the only two lines you need to change
 m4_define([user_agent_prefix],[1.83+])
-m4_define([peer_id_prefix],[-TR183Z-])
+m4_define([peer_id_prefix],[-TR183P-])
 
 AC_INIT([transmission],
         [user_agent_prefix],