removes an unnecessary restriction
diff --git a/ruby/grpc-demo.gemspec b/ruby/grpc-demo.gemspec
index 9d339dc..fa69eb2 100644
--- a/ruby/grpc-demo.gemspec
+++ b/ruby/grpc-demo.gemspec
@@ -17,7 +17,7 @@
   s.require_paths = ['lib']
   s.platform      = Gem::Platform::RUBY
 
-  s.add_dependency 'grpc', '~> 0.6.0'
+  s.add_dependency 'grpc', '~> 0.6'
 
   s.add_development_dependency 'bundler', '~> 1.7'
 end