diff --git a/mifiel.gemspec b/mifiel.gemspec
index 28e5eb5..9c2a97b 100644
--- a/mifiel.gemspec
+++ b/mifiel.gemspec
@@ -27,8 +27,8 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'rest-client', '>= 1.8'
 
   spec.add_development_dependency 'appraisal'
-  spec.add_development_dependency 'bump',       '~> 0.5', '>= 0.5.3'
-  spec.add_development_dependency 'bundler',    '~> 1.6'
+  spec.add_development_dependency 'bump', '~> 0.5', '>= 0.5.3'
+  spec.add_development_dependency 'bundler'
   spec.add_development_dependency 'byebug',     '~> 9.0', '< 9.0.6'
   spec.add_development_dependency 'pry-byebug', '~> 3.4', '>= 3.3.0'
   spec.add_development_dependency 'rake',       '~> 10.0'