diff --git a/lib/optparse.rb b/lib/optparse.rb
index 50641867f0..27e0843947 100644
--- a/lib/optparse.rb
+++ b/lib/optparse.rb
@@ -425,7 +425,7 @@
 #
 class OptionParser
   # The version string
-  OptionParser::Version = "0.5.0"
+  OptionParser::Version = "0.6.0"
 
   # :stopdoc:
   NoArgument = [NO_ARGUMENT = :NONE, nil].freeze