diff --git a/percentage.gemspec b/percentage.gemspec
index b1d150c..ccbe3ec 100644
--- a/percentage.gemspec
+++ b/percentage.gemspec
@@ -8,5 +8,6 @@ Gem::Specification.new do |s|
   s.description = 'A little library for working with percentages'
   s.summary = 'See description'
   s.files = Dir.glob('{lib,spec}/**/*') + %w(README.md Rakefile.rb percentage.gemspec)
+  s.add_development_dependency('rake', '~> 10.0.3')
   s.require_path = 'lib'
 end