diff --git a/underarmour.gemspec b/underarmour.gemspec
index 27205a9..1332bf1 100644
--- a/underarmour.gemspec
+++ b/underarmour.gemspec
@@ -30,7 +30,7 @@ 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", "~> 1.15"
+  spec.add_development_dependency "bundler", "~> 2.1"
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec", "~> 3.0"
   spec.add_development_dependency "pry"