diff --git a/bin/weecfg/tests/expected/weewx43_user_expected.conf b/bin/weecfg/tests/expected/weewx43_user_expected.conf
index 975452c9..2a869549 100644
--- a/bin/weecfg/tests/expected/weewx43_user_expected.conf
+++ b/bin/weecfg/tests/expected/weewx43_user_expected.conf
@@ -26,7 +26,7 @@ log_failure = True
 socket_timeout = 20
 
 # Do not modify this - it is used by setup.py when installing and updating.
-version = 4.5.0a3
+version = 4.5.0b1
 
 ##############################################################################
 
diff --git a/bin/weewx/__init__.py b/bin/weewx/__init__.py
index 62b5caec..c0672c94 100644
--- a/bin/weewx/__init__.py
+++ b/bin/weewx/__init__.py
@@ -7,7 +7,7 @@
 from __future__ import absolute_import
 import time
 
-__version__="4.5.0a3"
+__version__="4.5.0b1"
 
 # Holds the program launch time in unix epoch seconds:
 # Useful for calculating 'uptime.'
diff --git a/setup.py b/setup.py
index a6e12940..51c1296a 100755
--- a/setup.py
+++ b/setup.py
@@ -31,7 +31,7 @@ from distutils.command.install_lib import install_lib
 from distutils.core import setup
 from distutils.debug import DEBUG
 
-VERSION = "4.5.0a3"
+VERSION = "4.5.0b1"
 
 if sys.version_info < (2, 7):
     log.fatal('WeeWX requires Python V2.7 or greater.')
diff --git a/weewx.conf b/weewx.conf
index c66c8527..83b8769c 100644
--- a/weewx.conf
+++ b/weewx.conf
@@ -23,7 +23,7 @@ log_failure = True
 socket_timeout = 20
 
 # Do not modify this. It is used when installing and updating weewx.
-version = 4.5.0a3
+version = 4.5.0b1
 
 ##############################################################################