diff --git a/configure.in b/configure.in
index de0a9bbdeaa..04a8d045053 100644
--- a/configure.in
+++ b/configure.in
@@ -10,7 +10,7 @@ AC_CANONICAL_SYSTEM
 #
 # When changing major version number please also check switch statement
 # in mysqlbinlog::check_master_version().
-AM_INIT_AUTOMAKE(mysql, 5.1.20-beta)
+AM_INIT_AUTOMAKE(mysql, 5.1.21-beta)
 AM_CONFIG_HEADER(config.h)
 
 PROTOCOL_VERSION=10