diff --git a/Gemfile b/Gemfile
index afbd5abf..3b3dcd71 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,5 +4,5 @@ group :development do
   gem "rake", "13.0.6"
   gem "rake-compiler", "1.2.3"
   gem "test-unit", "3.6.1"
-  gem "test-unit-ruby-core", "1.0.1"
+  gem "test-unit-ruby-core", "1.0.5"
 end
diff --git a/Rakefile b/Rakefile
index 62a7b4ee..cd60025f 100644
--- a/Rakefile
+++ b/Rakefile
@@ -4,8 +4,9 @@ require "bundler/gem_tasks"
 
 require 'rdoc/task'
 
+spec = Gem::Specification.load("racc.gemspec")
+
 RDoc::Task.new(:docs) do |rd|
-  spec = Gem::Specification.load("racc.gemspec")
   rd.main = "README.en.rdoc"
   rd.rdoc_files.include(spec.files.find_all { |file_name|
     file_name =~ /^(bin|lib|ext)/ || file_name !~ /\//
@@ -47,6 +48,14 @@ end
   }
 end
 
+javasrc, = Dir.glob('ext/racc/**/Cparse.java')
+task :compile => javasrc do
+  code = File.binread(javasrc)
+  if code.sub!(/RACC_VERSION\s*=\s*"\K([^"]*)(?=")/) {|v| break if v == spec.version; spec.version}
+    File.binwrite(javasrc, code)
+  end
+end
+
 lib_dir = nil # for dummy rake/extensiontask.rb at ruby test-bundled-gems
 if jruby?
   # JRUBY
diff --git a/ext/racc/com/headius/racc/Cparse.java b/ext/racc/com/headius/racc/Cparse.java
index 106e2db8..1f927c25 100644
--- a/ext/racc/com/headius/racc/Cparse.java
+++ b/ext/racc/com/headius/racc/Cparse.java
@@ -45,7 +45,7 @@
 import org.jruby.runtime.load.Library;
 
 public class Cparse implements Library {
-    public static final String RACC_VERSION = "1.7.2"; // TODO: parse from Cparse.c
+    public static final String RACC_VERSION = "1.7.3.dev.1"; // TODO: parse from Cparse.c
 
     public enum TokenType {
         DEFAULT(-1),
diff --git a/lib/racc/info.rb b/lib/racc/info.rb
index 6129f9b9..34acda54 100644
--- a/lib/racc/info.rb
+++ b/lib/racc/info.rb
@@ -12,7 +12,7 @@
 #++
 
 module Racc
-  VERSION   = '1.7.2'
+  VERSION   = '1.7.3.dev.1'
   Version = VERSION
   Copyright = 'Copyright (c) 1999-2006 Minero Aoki'
 end