diff --git a/Makefile b/Makefile
index 57243f670..2a40b23a1 100644
--- a/Makefile
+++ b/Makefile
@@ -35,3 +35,6 @@ docker-push:
 
 cluster-test:
 	bundle exec rspec ./cluster_spec.rb
+
+prettier:
+	bundle exec rubocop -A -d --cache true --parallel
diff --git a/lib/twilio-ruby/base/client_base.rb b/lib/twilio-ruby/base/client_base.rb
index 9b8460b5e..e89892cf5 100644
--- a/lib/twilio-ruby/base/client_base.rb
+++ b/lib/twilio-ruby/base/client_base.rb
@@ -111,7 +111,10 @@ def generate_headers(method, headers)
 
         user_agent_extensions.each { |extension| headers['User-Agent'] += " #{extension}" }
 
-        headers['Content-Type'] = 'application/x-www-form-urlencoded' if method == 'POST' && !headers['Content-Type']
+        if ['POST', 'PUT'].include?(method) && !headers['Content-Type']
+          headers['Content-Type'] =
+            'application/x-www-form-urlencoded'
+        end
 
         headers['Accept'] = 'application/json' unless headers['Accept']
         headers