@@ -301,7 +301,8 @@ def create_response(env)
       {
         status: hash[:status],
         body: hash[:body] || hash[:response_body],
-        response_headers: hash[:response_headers]
+        response_headers: hash[:response_headers],
+        reason_phrase: hash[:reason_phrase]
       }
     end
 
 
@@ -142,7 +142,8 @@ def serializable_hash
         {
           status: @payload[:status],
           body: @payload[:body],
-          response_headers: @payload[:response_headers]
+          response_headers: @payload[:response_headers],
+          reason_phrase: @payload[:reason_phrase]
         }
       end
 
 
@@ -200,7 +200,7 @@
   end
 
   describe 'response unboxing' do
-    subject { described_class.new(status: 200, response_headers: {}, body: 'Hi!') }
+    subject { described_class.new(status: 200, response_headers: {}, body: 'Hi!', reason_phrase: 'Success') }
 
     let(:env) { { method: :get } }
     let(:response) { subject.to_response(env) }
@@ -224,6 +224,10 @@
     it 'merges the body' do
       expect(response.body).to eq('Hi!')
     end
+
+    it 'merges the reason phrase' do
+      expect(response.reason_phrase).to eq('Success') if response.respond_to?(:reason_phrase)
+    end
   end
 
   describe 'remove age before caching and normalize max-age if non-zero age present' do
Original file line number	Diff line number	Diff line change
`@@ -301,7 +301,8 @@ def create_response(env)`
`301`	`301`	`{`
`302`	`302`	`status: hash[:status],`
`303`	`303`	`body: hash[:body] \|\| hash[:response_body],`
`304`		`- response_headers: hash[:response_headers]`
	`304`	`+ response_headers: hash[:response_headers],`
	`305`	`+ reason_phrase: hash[:reason_phrase]`
`305`	`306`	`}`
`306`	`307`	`end`
`307`	`308`
Original file line number	Diff line number	Diff line change
`@@ -142,7 +142,8 @@ def serializable_hash`
`142`	`142`	`{`
`143`	`143`	`status: @payload[:status],`
`144`	`144`	`body: @payload[:body],`
`145`		`- response_headers: @payload[:response_headers]`
	`145`	`+ response_headers: @payload[:response_headers],`
	`146`	`+ reason_phrase: @payload[:reason_phrase]`
`146`	`147`	`}`
`147`	`148`	`end`
`148`	`149`