diff --git a/awspec.gemspec b/awspec.gemspec
index 4c6f728aa..9786b0314 100644
--- a/awspec.gemspec
+++ b/awspec.gemspec
@@ -29,7 +29,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'rspec-its'
   spec.add_runtime_dependency 'term-ansicolor'
   spec.add_runtime_dependency 'thor'
-  spec.add_development_dependency 'bundler', '~> 1.9'
+  spec.add_development_dependency 'bundler', '>= 1.9', '< 2.1'
   spec.add_development_dependency 'octorelease'
   spec.add_development_dependency 'pry'
   spec.add_development_dependency 'rake', '~> 12.0'