diff --git a/lib/gitlab/git/diff_collection.rb b/lib/gitlab/git/diff_collection.rb
index 6a601561c2a7995408be20c62870500e417f4691..219c69893ad3514d710faf64661d1b1812e268be 100644
--- a/lib/gitlab/git/diff_collection.rb
+++ b/lib/gitlab/git/diff_collection.rb
@@ -42,12 +42,10 @@ def each(&block)
         return if @overflow
         return if @iterator.nil?
 
-        Gitlab::GitalyClient.migrate(:commit_raw_diffs) do |is_enabled|
-          if is_enabled && @iterator.is_a?(Gitlab::GitalyClient::DiffStitcher)
-            each_gitaly_patch(&block)
-          else
-            each_rugged_patch(&block)
-          end
+        if @iterator.is_a?(Gitlab::GitalyClient::DiffStitcher)
+          each_gitaly_patch(&block)
+        else
+          each_serialized_patch(&block)
         end
 
         @populated = true
@@ -118,7 +116,7 @@ def each_gitaly_patch
         end
       end
 
-      def each_rugged_patch
+      def each_serialized_patch
         i = @array.length
 
         @iterator.each do |raw|
diff --git a/lib/gitlab/git/repository.rb b/lib/gitlab/git/repository.rb
index 29b3663a52a5c67af7fe94733761eda18f83c643..6f0632addfa9c3929b37e269751a789dcee1f2d8 100644
--- a/lib/gitlab/git/repository.rb
+++ b/lib/gitlab/git/repository.rb
@@ -555,13 +555,7 @@ def merged_branch_names(branch_names = [])
       # diff options.  The +options+ hash can also include :break_rewrites to
       # split larger rewrites into delete/add pairs.
       def diff(from, to, options = {}, *paths)
-        iterator = gitaly_migrate(:diff_between) do |is_enabled|
-          if is_enabled
-            gitaly_commit_client.diff(from, to, options.merge(paths: paths))
-          else
-            diff_patches(from, to, options, *paths)
-          end
-        end
+        iterator = gitaly_commit_client.diff(from, to, options.merge(paths: paths))
 
         Gitlab::Git::DiffCollection.new(iterator, options)
       end
diff --git a/lib/gitlab/workhorse.rb b/lib/gitlab/workhorse.rb
index e893e46ee86d620a7e2b7e906124f68c3f1d5545..79483ee05f8c67a443ad2e4d7e1e48606b27547e 100644
--- a/lib/gitlab/workhorse.rb
+++ b/lib/gitlab/workhorse.rb
@@ -91,16 +91,12 @@ def send_git_snapshot(repository)
       end
 
       def send_git_diff(repository, diff_refs)
-        params = if Gitlab::GitalyClient.feature_enabled?(:workhorse_send_git_diff, status: Gitlab::GitalyClient::MigrationStatus::OPT_OUT)
-                   {
-                     'GitalyServer' => gitaly_server_hash(repository),
-                     'RawDiffRequest' => Gitaly::RawDiffRequest.new(
-                       gitaly_diff_or_patch_hash(repository, diff_refs)
-                     ).to_json
-                   }
-                 else
-                   workhorse_diff_or_patch_hash(repository, diff_refs)
-                 end
+        params = {
+          'GitalyServer' => gitaly_server_hash(repository),
+          'RawDiffRequest' => Gitaly::RawDiffRequest.new(
+            gitaly_diff_or_patch_hash(repository, diff_refs)
+          ).to_json
+        }
 
         [
           SEND_DATA_HEADER,
diff --git a/spec/lib/gitlab/workhorse_spec.rb b/spec/lib/gitlab/workhorse_spec.rb
index 660671cefaf923cbdf63112331ab98e122074f7b..570580e0cfca06ace6905ef8e54f342d7fa3a963 100644
--- a/spec/lib/gitlab/workhorse_spec.rb
+++ b/spec/lib/gitlab/workhorse_spec.rb
@@ -143,34 +143,22 @@ def workhorse(ca_pem: nil)
     let(:diff_refs) { double(base_sha: "base", head_sha: "head") }
     subject { described_class.send_git_diff(repository, diff_refs) }
 
-    context 'when Gitaly workhorse_send_git_diff feature is enabled' do
-      it 'sets the header correctly' do
-        key, command, params = decode_workhorse_header(subject)
-
-        expect(key).to eq("Gitlab-Workhorse-Send-Data")
-        expect(command).to eq("git-diff")
-        expect(params).to eq({
-          'GitalyServer' => {
-            address: Gitlab::GitalyClient.address(project.repository_storage),
-            token: Gitlab::GitalyClient.token(project.repository_storage)
-          },
-          'RawDiffRequest' => Gitaly::RawDiffRequest.new(
-            repository: repository.gitaly_repository,
-            left_commit_id: 'base',
-            right_commit_id: 'head'
-          ).to_json
-        }.deep_stringify_keys)
-      end
-    end
-
-    context 'when Gitaly workhorse_send_git_diff feature is disabled', :disable_gitaly do
-      it 'sets the header correctly' do
-        key, command, params = decode_workhorse_header(subject)
+    it 'sets the header correctly' do
+      key, command, params = decode_workhorse_header(subject)
 
-        expect(key).to eq("Gitlab-Workhorse-Send-Data")
-        expect(command).to eq("git-diff")
-        expect(params).to eq("RepoPath" => repository.path_to_repo, "ShaFrom" => "base", "ShaTo" => "head")
-      end
+      expect(key).to eq("Gitlab-Workhorse-Send-Data")
+      expect(command).to eq("git-diff")
+      expect(params).to eq({
+        'GitalyServer' => {
+          address: Gitlab::GitalyClient.address(project.repository_storage),
+          token: Gitlab::GitalyClient.token(project.repository_storage)
+        },
+        'RawDiffRequest' => Gitaly::RawDiffRequest.new(
+          repository: repository.gitaly_repository,
+          left_commit_id: 'base',
+          right_commit_id: 'head'
+        ).to_json
+      }.deep_stringify_keys)
     end
   end