diff --git a/README b/README
index 871ad314d..dabfb8c03 100644
--- a/README
+++ b/README
@@ -3,7 +3,7 @@
 CANTERA
 *******
 
-Version 2.1a1 (development)
+Version 2.1.0b1 (development)
 
 License Information
 ===================
diff --git a/SConstruct b/SConstruct
index 108a3ba63..f5a1b631f 100644
--- a/SConstruct
+++ b/SConstruct
@@ -601,7 +601,7 @@ config_options = [
         name recognized by the 'dot' program. On linux systems, this
         should be lowercase 'helvetica'.""",
      'Helvetica'),
-    ('cantera_version', '', '2.1a1')
+    ('cantera_version', '', '2.1.0b1')
 ]
 
 opts.AddVariables(*config_options)
diff --git a/configure.ac b/configure.ac
index 60994e2d7..ff58f4ca0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ(2.61)
-AC_INIT([cantera], [2.1a1], [nick@ices.utexas.edu])
+AC_INIT([cantera], [2.1.0b1], [nick@ices.utexas.edu])
 AC_CONFIG_HEADER(config.h)
 AC_CONFIG_AUX_DIR([build-aux])
 #AX_ENABLE_BUILDDIR
diff --git a/doc/sphinx/conf.py b/doc/sphinx/conf.py
index 3c2e00e87..029d012ac 100644
--- a/doc/sphinx/conf.py
+++ b/doc/sphinx/conf.py
@@ -75,7 +75,7 @@ copyright = u'2012, Cantera Developers'
 # The short X.Y version.
 version = '2.1'
 # The full version, including alpha/beta/rc tags.
-release = '2.1a1'
+release = '2.1.0b1'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.