diff --git a/git-contributors.gemspec b/git-contributors.gemspec
index ca4151c..774d6f6 100644
--- a/git-contributors.gemspec
+++ b/git-contributors.gemspec
@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "bundler", "~> 1.5"
+  spec.add_development_dependency "bundler", "~> 2.2", ">= 2.2.33"
   spec.add_development_dependency "rake", "~> 10"
 
   spec.add_dependency 'diffy', '~> 3.0'