diff --git a/configure.ac b/configure.ac
index e7ceb00299..d6035ef358 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,7 +12,7 @@ AC_PREREQ(2.59)
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[2.3.0-pre],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[2.3.1-pre],[protobuf@googlegroups.com],[protobuf])
 
 
 AC_CONFIG_SRCDIR(src/google/protobuf/message.cc)
diff --git a/java/pom.xml b/java/pom.xml
index dd28a46dae..94f1d7f68b 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -10,7 +10,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java</artifactId>
-  <version>2.3.0-pre</version>
+  <version>2.3.1-pre</version>
   <packaging>jar</packaging>
   <name>Protocol Buffer Java API</name>
   <description>
diff --git a/python/setup.py b/python/setup.py
index a547261670..8c97439f2e 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -98,7 +98,7 @@ if __name__ == '__main__':
     generate_proto("../src/google/protobuf/descriptor.proto")
 
   setup(name = 'protobuf',
-        version = '2.3.0-pre',
+        version = '2.3.1-pre',
         packages = [ 'google' ],
         namespace_packages = [ 'google' ],
         test_suite = 'setup.MakeTestSuite',
diff --git a/src/google/protobuf/compiler/plugin.pb.h b/src/google/protobuf/compiler/plugin.pb.h
index f8f805354f..bd6bf63c48 100644
--- a/src/google/protobuf/compiler/plugin.pb.h
+++ b/src/google/protobuf/compiler/plugin.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 2003000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 2003001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/descriptor.pb.h b/src/google/protobuf/descriptor.pb.h
index 2743b6f5f9..205c5476ec 100644
--- a/src/google/protobuf/descriptor.pb.h
+++ b/src/google/protobuf/descriptor.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 2003000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 2003001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index 551ee4aac6..b8d2ecb9e5 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -83,7 +83,7 @@ namespace internal {
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 2003000
+#define GOOGLE_PROTOBUF_VERSION 2003001
 
 // The minimum library version which works with the current version of the
 // headers.