diff --git a/sidetiq.gemspec b/sidetiq.gemspec
index 96ae674..ace5007 100644
--- a/sidetiq.gemspec
+++ b/sidetiq.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |gem|
 
   gem.add_dependency 'sidekiq',   '>= 4.0.0'
   gem.add_dependency 'celluloid', '>= 0.17.3'
-  gem.add_dependency 'ice_cube',  '0.13.2'
+  gem.add_dependency 'ice_cube',  '~> 0.13.2'
 
   gem.add_development_dependency 'rake'
   gem.add_development_dependency 'sinatra'