onebox.gemspec in onebox-1.9.19 vs onebox.gemspec in onebox-1.9.20

@@ -36,10 +36,10 @@
   spec.add_development_dependency 'rubocop', '~> 0.50'
   spec.add_development_dependency 'twitter', '~> 4.8'
   spec.add_development_dependency 'guard-rspec', '~> 4.2.8'
   spec.add_development_dependency 'sinatra', '~> 1.4'
   spec.add_development_dependency 'sinatra-contrib', '~> 1.4'
-  spec.add_development_dependency 'haml', '~> 4.0'
+  spec.add_development_dependency 'haml', '~> 5.1'
   spec.add_development_dependency 'listen', '~> 2.10.0'
 
   spec.required_ruby_version = '>=2.4.0'
 end