diff --git a/topdown.gemspec b/topdown.gemspec
index 6176a6c..89bf40f 100644
--- a/topdown.gemspec
+++ b/topdown.gemspec
@@ -24,7 +24,7 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{^exe/}) {|f| File.basename(f)}
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "bundler", "~> 2.0.1"
+  spec.add_development_dependency "bundler", "~> 2.2.15"
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.0"
 end