diff --git a/configure.ac b/configure.ac
index c33c05d10..d10cff859 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,8 +3,8 @@ dnl STATUS: "X" for prerelease beta builds,
 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],[1.72])
-m4_define([peer_id_prefix],[-TR1720-])
+m4_define([user_agent_prefix],[1.72+])
+m4_define([peer_id_prefix],[-TR172Z-])
 
 AC_INIT([transmission],
         [user_agent_prefix],
diff --git a/macosx/version.sh b/macosx/version.sh
index 0f1f17fce..1fe43d556 100755
--- a/macosx/version.sh
+++ b/macosx/version.sh
@@ -7,8 +7,8 @@
 #         "Z" for unsupported trunk builds,
 #         "0" for stable, supported releases
 # these should be the only two lines you need to change
-PEERID_PREFIX="-TR1720-"
-USERAGENT_PREFIX="1.72"
+PEERID_PREFIX="-TR172Z-"
+USERAGENT_PREFIX="1.72+"
 
 SVN_REVISION=`find -E ./libtransmission ./macosx                     \
                   -regex ".*\.([chmp]|cpp|po|sh)"                    \