diff --git a/.github/workflows/edge.yml b/.github/workflows/edge.yml
index c617da14e1..cfa629b0b8 100644
--- a/.github/workflows/edge.yml
+++ b/.github/workflows/edge.yml
@@ -7,7 +7,12 @@ jobs:
       fail-fast: false
       matrix:
         ruby: ['2.7', '3.0', '3.1', '3.2', '3.3', ruby-head, truffleruby-head, jruby-head]
-        gemfile: [rails_edge, rack_edge, rack_3_0]
+        gemfile: [rails_edge, rack_edge]
+        exclude:
+          - ruby: '2.7'
+            gemfile: rails_edge
+          - ruby: '3.0'
+            gemfile: rails_edge
     runs-on: ubuntu-latest
     continue-on-error: true
     env:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6ba50c99a..ac5cb93f87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 * [#2373](https://github.com/ruby-grape/grape/pull/2373): Fix markdown files for following 1-line format - [@jcagarcia](https://github.com/jcagarcia).
 * [#2382](https://github.com/ruby-grape/grape/pull/2382): Fix values validator for params wrapped in `with` block - [@numbata](https://github.com/numbata).
 * [#2387](https://github.com/ruby-grape/grape/pull/2387): Fix rubygems version within workflows - [@ericproulx](https://github.com/ericproulx).
+* [#2405](https://github.com/ruby-grape/grape/pull/2405): Fix edge workflow - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 ### 2.0.0 (2023/11/11)
diff --git a/spec/grape/api_spec.rb b/spec/grape/api_spec.rb
index dc31094afc..97c2dbff07 100644
--- a/spec/grape/api_spec.rb
+++ b/spec/grape/api_spec.rb
@@ -688,7 +688,7 @@ class DummyFormatClass
         'example'
       end
       put '/example'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'text/plain'
+      expect(last_response.content_type).to eql 'text/plain'
     end
 
     describe 'adds an OPTIONS route that' do
@@ -1195,7 +1195,7 @@ class DummyFormatClass
 
     it 'sets content type for txt format' do
       get '/foo'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('text/plain')
+      expect(last_response.content_type).to eq('text/plain')
     end
 
     it 'does not set Cache-Control' do
@@ -1205,22 +1205,22 @@ class DummyFormatClass
 
     it 'sets content type for xml' do
       get '/foo.xml'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('application/xml')
+      expect(last_response.content_type).to eq('application/xml')
     end
 
     it 'sets content type for json' do
       get '/foo.json'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('application/json')
+      expect(last_response.content_type).to eq('application/json')
     end
 
     it 'sets content type for serializable hash format' do
       get '/foo.serializable_hash'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('application/json')
+      expect(last_response.content_type).to eq('application/json')
     end
 
     it 'sets content type for binary format' do
       get '/foo.binary'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('application/octet-stream')
+      expect(last_response.content_type).to eq('application/octet-stream')
     end
 
     it 'returns raw data when content type binary' do
@@ -1229,7 +1229,7 @@ class DummyFormatClass
       subject.format :binary
       subject.get('/binary_file') { File.binread(image_filename) }
       get '/binary_file'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('application/octet-stream')
+      expect(last_response.content_type).to eq('application/octet-stream')
       expect(last_response.body).to eq(file)
     end
 
@@ -1241,8 +1241,8 @@ class DummyFormatClass
 
       subject.get('/file') { stream test_file }
       get '/file'
-      expect(last_response.headers[Rack::CONTENT_LENGTH]).to eq('25')
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('text/plain')
+      expect(last_response.content_length).to eq(25)
+      expect(last_response.content_type).to eq('text/plain')
       expect(last_response.body).to eq(file_content)
     end
 
@@ -1252,12 +1252,12 @@ class DummyFormatClass
         blk.yield ' file content'
       end
 
-      subject.use Rack::Chunked
+      subject.use Gem::Version.new(Rack.release) < Gem::Version.new('3') ? Rack::Chunked : ChunkedResponse
       subject.get('/stream') { stream test_stream }
       get '/stream', {}, 'HTTP_VERSION' => 'HTTP/1.1', 'SERVER_PROTOCOL' => 'HTTP/1.1'
 
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eq('text/plain')
-      expect(last_response.headers[Rack::CONTENT_LENGTH]).to be_nil
+      expect(last_response.content_type).to eq('text/plain')
+      expect(last_response.content_length).to be_nil
       expect(last_response.headers[Rack::CACHE_CONTROL]).to eq('no-cache')
       expect(last_response.headers[Grape::Http::Headers::TRANSFER_ENCODING]).to eq('chunked')
 
@@ -1267,7 +1267,7 @@ class DummyFormatClass
     it 'sets content type for error' do
       subject.get('/error') { error!('error in plain text', 500) }
       get '/error'
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'text/plain'
+      expect(last_response.content_type).to eql 'text/plain'
     end
 
     it 'sets content type for json error' do
@@ -1275,7 +1275,7 @@ class DummyFormatClass
       subject.get('/error') { error!('error in json', 500) }
       get '/error.json'
       expect(last_response.status).to be 500
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'application/json'
+      expect(last_response.content_type).to eql 'application/json'
     end
 
     it 'sets content type for xml error' do
@@ -1283,7 +1283,7 @@ class DummyFormatClass
       subject.get('/error') { error!('error in xml', 500) }
       get '/error'
       expect(last_response.status).to be 500
-      expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'application/xml'
+      expect(last_response.content_type).to eql 'application/xml'
     end
 
     it 'includes extension in format' do
@@ -1313,12 +1313,12 @@ class DummyFormatClass
 
       it 'sets content type' do
         get '/custom.custom'
-        expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'application/custom'
+        expect(last_response.content_type).to eql 'application/custom'
       end
 
       it 'sets content type for error' do
         get '/error.custom'
-        expect(last_response.headers[Rack::CONTENT_TYPE]).to eql 'application/custom'
+        expect(last_response.content_type).to eql 'application/custom'
       end
     end
 
@@ -1342,7 +1342,7 @@ class DummyFormatClass
             image_filename = 'grape.png'
             post url, file: Rack::Test::UploadedFile.new(image_filename, content_type, true)
             expect(last_response.status).to eq(201)
-            expect(last_response.headers[Rack::CONTENT_TYPE]).to eq(content_type)
+            expect(last_response.content_type).to eq(content_type)
             expect(last_response.headers['Content-Disposition']).to eq("attachment; filename*=UTF-8''grape.png")
             File.open(image_filename, 'rb') do |io|
               expect(last_response.body).to eq io.read
@@ -1358,7 +1358,7 @@ class DummyFormatClass
           filename = __FILE__
           post '/attachment.rb', file: Rack::Test::UploadedFile.new(filename, content_type, true)
           expect(last_response.status).to eq(201)
-          expect(last_response.headers[Rack::CONTENT_TYPE]).to eq(content_type)
+          expect(last_response.content_type).to eq(content_type)
           expect(last_response.headers['Content-Disposition']).to eq("attachment; filename*=UTF-8''api_spec.rb")
           File.open(filename, 'rb') do |io|
             expect(last_response.body).to eq io.read
diff --git a/spec/grape/endpoint_spec.rb b/spec/grape/endpoint_spec.rb
index 94d0443c37..77dd116c00 100644
--- a/spec/grape/endpoint_spec.rb
+++ b/spec/grape/endpoint_spec.rb
@@ -490,7 +490,7 @@ def app
       end
 
       it 'responses with given content type in headers' do
-        expect(last_response.headers[Rack::CONTENT_TYPE]).to eq 'application/json; charset=utf-8'
+        expect(last_response.content_type).to eq 'application/json; charset=utf-8'
       end
     end
 
@@ -650,7 +650,7 @@ def app
       end
       get '/hey'
       expect(last_response.status).to eq 302
-      expect(last_response.headers['Location']).to eq '/ha'
+      expect(last_response.location).to eq '/ha'
       expect(last_response.body).to eq 'This resource has been moved temporarily to /ha.'
     end
 
@@ -660,7 +660,7 @@ def app
       end
       post '/hey', {}, 'HTTP_VERSION' => 'HTTP/1.1'
       expect(last_response.status).to eq 303
-      expect(last_response.headers['Location']).to eq '/ha'
+      expect(last_response.location).to eq '/ha'
       expect(last_response.body).to eq 'An alternate resource is located at /ha.'
     end
 
@@ -670,7 +670,7 @@ def app
       end
       get '/hey'
       expect(last_response.status).to eq 301
-      expect(last_response.headers['Location']).to eq '/ha'
+      expect(last_response.location).to eq '/ha'
       expect(last_response.body).to eq 'This resource has been moved permanently to /ha.'
     end
 
diff --git a/spec/grape/entity_spec.rb b/spec/grape/entity_spec.rb
index 425edf0031..7eaa0fae87 100644
--- a/spec/grape/entity_spec.rb
+++ b/spec/grape/entity_spec.rb
@@ -236,7 +236,7 @@ def initialize(args)
       end
       get '/example'
       expect(last_response.status).to eq(200)
-      expect(last_response.headers['Content-type']).to eq('application/xml')
+      expect(last_response.content_type).to eq('application/xml')
       expect(last_response.body).to eq <<~XML
         <?xml version="1.0" encoding="UTF-8"?>
         <hash>
@@ -266,7 +266,7 @@ def initialize(args)
       end
       get '/example'
       expect(last_response.status).to eq(200)
-      expect(last_response.headers['Content-type']).to eq('application/json')
+      expect(last_response.content_type).to eq('application/json')
       expect(last_response.body).to eq('{"example":{"name":"johnnyiller"}}')
     end
 
@@ -298,7 +298,7 @@ def initialize(args)
 
       get '/example?callback=abcDef'
       expect(last_response.status).to eq(200)
-      expect(last_response.headers['Content-type']).to eq('application/javascript')
+      expect(last_response.content_type).to eq('application/javascript')
       expect(last_response.body).to include 'abcDef({"example":{"name":"johnnyiller"}})'
     end
 
diff --git a/spec/grape/middleware/base_spec.rb b/spec/grape/middleware/base_spec.rb
index cbba974e1a..3be95be1f5 100644
--- a/spec/grape/middleware/base_spec.rb
+++ b/spec/grape/middleware/base_spec.rb
@@ -93,7 +93,7 @@
       end
 
       it 'header' do
-        expect(subject.response.header).to have_key(:abc)
+        expect(subject.response.headers).to have_key(:abc)
       end
 
       it 'returns the memoized Rack::Response instance' do
@@ -115,7 +115,7 @@
       end
 
       it 'header' do
-        expect(subject.response.header).to have_key(:abc)
+        expect(subject.response.headers).to have_key(:abc)
       end
 
       it 'returns the memoized Rack::Response instance' do
diff --git a/spec/support/basic_auth_encode_helpers.rb b/spec/support/basic_auth_encode_helpers.rb
index 78e21e6c80..00c3c61497 100644
--- a/spec/support/basic_auth_encode_helpers.rb
+++ b/spec/support/basic_auth_encode_helpers.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'base64'
+
 module Spec
   module Support
     module Helpers
diff --git a/spec/support/chunked_response.rb b/spec/support/chunked_response.rb
new file mode 100644
index 0000000000..41defe87e6
--- /dev/null
+++ b/spec/support/chunked_response.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+# this is a copy of Rack::Chunked which has been removed in rack > 3.0
+
+class ChunkedResponse
+  class Body
+    TERM = "\r\n"
+    TAIL = "0#{TERM}"
+
+    # Store the response body to be chunked.
+    def initialize(body)
+      @body = body
+    end
+
+    # For each element yielded by the response body, yield
+    # the element in chunked encoding.
+    def each(&block)
+      term = TERM
+      @body.each do |chunk|
+        size = chunk.bytesize
+        next if size == 0
+
+        yield [size.to_s(16), term, chunk.b, term].join
+      end
+      yield TAIL
+      yield_trailers(&block)
+      yield term
+    end
+
+    # Close the response body if the response body supports it.
+    def close
+      @body.close if @body.respond_to?(:close)
+    end
+
+    private
+
+    # Do nothing as this class does not support trailer headers.
+    def yield_trailers; end
+  end
+
+  class TrailerBody < Body
+    private
+
+    # Yield strings for each trailer header.
+    def yield_trailers
+      @body.trailers.each_pair do |k, v|
+        yield "#{k}: #{v}\r\n"
+      end
+    end
+  end
+
+  def initialize(app)
+    @app = app
+  end
+
+  def call(env)
+    status, headers, body = response = @app.call(env)
+
+    if !Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.key?(status.to_i) &&
+       !headers[Rack::CONTENT_LENGTH] &&
+       !headers[Rack::TRANSFER_ENCODING]
+
+      headers[Rack::TRANSFER_ENCODING] = 'chunked'
+      response[2] = if headers['trailer']
+                      TrailerBody.new(body)
+                    else
+                      Body.new(body)
+                    end
+    end
+
+    response
+  end
+end