bump version number
diff --git a/lib/rb/thrift.gemspec b/lib/rb/thrift.gemspec
index 1977ec4..625c6a4 100644
--- a/lib/rb/thrift.gemspec
+++ b/lib/rb/thrift.gemspec
@@ -3,7 +3,7 @@
 
 Gem::Specification.new do |s|
   s.name        = 'thrift'
-  s.version     = '0.21.0'
+  s.version     = '0.22.0'
   s.authors     = ['Apache Thrift Developers']
   s.email       = ['dev@thrift.apache.org']
   s.homepage    = 'http://thrift.apache.org'