diff --git a/celluloid-pmap.gemspec b/celluloid-pmap.gemspec
index 810d045..932cadd 100644
--- a/celluloid-pmap.gemspec
+++ b/celluloid-pmap.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |gem|
   gem.add_dependency('celluloid', ' >= 0.16')
 
   gem.add_development_dependency "rake"
-  gem.add_development_dependency "rspec", "2.99"
+  gem.add_development_dependency "rspec", "3.10.0"
   gem.add_development_dependency "pry"
   gem.add_development_dependency 'appraisal', '~> 2.1', '>= 2.1'
 end