diff --git a/README.rst b/README.rst
index ae8255a8c..1100febb2 100644
--- a/README.rst
+++ b/README.rst
@@ -3,7 +3,7 @@
 CANTERA
 *******
 
-Version 2.2.0 (stable)
+Version 2.3.0a1 (development)
 
 License Information
 ===================
diff --git a/SConstruct b/SConstruct
index 3ee12182d..5118c7151 100644
--- a/SConstruct
+++ b/SConstruct
@@ -582,7 +582,7 @@ config_options = [
            with a prefix like '/opt/cantera'. 'debian' installs to the stage
            directory in a layout used for generating Debian packages.""",
      defaults.fsLayout, ('standard','compact','debian')),
-    ('cantera_version', '', '2.2.0')
+    ('cantera_version', '', '2.3.0a1')
 ]
 
 opts.AddVariables(*config_options)
diff --git a/doc/doxygen/Doxyfile b/doc/doxygen/Doxyfile
index 689fdc82f..d615bd8ae 100644
--- a/doc/doxygen/Doxyfile
+++ b/doc/doxygen/Doxyfile
@@ -34,7 +34,7 @@ PROJECT_NAME           = Cantera
 # This could be handy for archiving the generated documentation or
 # if some version control system is used.
 
-PROJECT_NUMBER         = 2.2
+PROJECT_NUMBER         = 2.3.0a1
 
 # The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute)
 # base path where the generated documentation will be put.