diff --git a/config/feature_flags/development/ci_fix_max_includes.yml b/config/feature_flags/development/ci_fix_max_includes.yml
new file mode 100644
index 0000000000000000000000000000000000000000..8abcf2640cd76a310d8a4b72b0ba40bbcd54e147
--- /dev/null
+++ b/config/feature_flags/development/ci_fix_max_includes.yml
@@ -0,0 +1,8 @@
+---
+name: ci_fix_max_includes
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/111391
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/390909
+milestone: '15.9'
+type: development
+group: group::pipeline authoring
+default_enabled: false
diff --git a/lib/gitlab/ci/config/external/context.rb b/lib/gitlab/ci/config/external/context.rb
index 138e79db33181d05a03d015ac46dc346070be3f4..71e21f06f19dd968e7b1b5a28b13335ca1ed6f4b 100644
--- a/lib/gitlab/ci/config/external/context.rb
+++ b/lib/gitlab/ci/config/external/context.rb
@@ -27,7 +27,7 @@ def initialize(
             @user = user
             @parent_pipeline = parent_pipeline
             @variables = variables || Ci::Variables::Collection.new
-            @expandset = Set.new
+            @expandset = Feature.enabled?(:ci_fix_max_includes, project) ? [] : Set.new
             @execution_deadline = 0
             @logger = logger || Gitlab::Ci::Pipeline::Logger.new(project: project)
             @max_includes = MAX_INCLUDES
diff --git a/lib/gitlab/ci/config/external/mapper/verifier.rb b/lib/gitlab/ci/config/external/mapper/verifier.rb
index beb4dd1add7f8fbc5e8b3db9e5aa3a6726ca0d78..896bd18a3aa8f9f7452634be33cba47c5c653c46 100644
--- a/lib/gitlab/ci/config/external/mapper/verifier.rb
+++ b/lib/gitlab/ci/config/external/mapper/verifier.rb
@@ -15,6 +15,11 @@ def process_without_instrumentation(files)
               end
 
               files.each do |file|
+                if ::Feature.enabled?(:ci_fix_max_includes, context.project)
+                  context.expandset << file
+                  verify_max_includes!
+                end
+
                 verify_execution_time!
 
                 file.validate_location!
@@ -25,31 +30,44 @@ def process_without_instrumentation(files)
               # We do not combine the loops because we need to load the content of all files before continuing
               # to call `BatchLoader` for all locations.
               files.each do |file| # rubocop:disable Style/CombinableLoops
-                # Checking the max includes will be changed with https://gitlab.com/gitlab-org/gitlab/-/issues/367150
-                verify_max_includes!
+                verify_max_includes! if ::Feature.disabled?(:ci_fix_max_includes, context.project)
+
                 verify_execution_time!
 
                 file.validate_content! if file.valid?
                 file.load_and_validate_expanded_hash! if file.valid?
 
-                context.expandset.add(file)
+                context.expandset.add(file) if ::Feature.disabled?(:ci_fix_max_includes, context.project)
               end
             end
 
             # Will be removed with the FF ci_batch_request_for_local_and_project_includes
             def legacy_process_without_instrumentation(files)
               files.select do |file|
-                verify_max_includes!
-                verify_execution_time!
+                if ::Feature.enabled?(:ci_fix_max_includes, context.project)
+                  context.expandset << file
+                  verify_max_includes!
 
-                file.validate!
+                  verify_execution_time!
 
-                context.expandset.add(file)
+                  file.validate!
+                else
+                  verify_max_includes!
+                  verify_execution_time!
+
+                  file.validate!
+
+                  context.expandset.add(file)
+                end
               end
             end
 
             def verify_max_includes!
-              return if context.expandset.count < context.max_includes
+              if ::Feature.enabled?(:ci_fix_max_includes, context.project)
+                return if context.expandset.count <= context.max_includes
+              else
+                return if context.expandset.count < context.max_includes # rubocop:disable Style/IfInsideElse
+              end
 
               raise Mapper::TooManyIncludesError, "Maximum of #{context.max_includes} nested includes are allowed!"
             end
diff --git a/spec/lib/gitlab/ci/config/external/context_spec.rb b/spec/lib/gitlab/ci/config/external/context_spec.rb
index 40702e7540442bfdafe5c2754aebce12be1a6c4d..73167be40d7803c9b066f9005bd538013f963d99 100644
--- a/spec/lib/gitlab/ci/config/external/context_spec.rb
+++ b/spec/lib/gitlab/ci/config/external/context_spec.rb
@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Ci::Config::External::Context do
+RSpec.describe Gitlab::Ci::Config::External::Context, feature_category: :pipeline_authoring do
   let(:project) { build(:project) }
   let(:user) { double('User') }
   let(:sha) { '12345' }
@@ -14,7 +14,7 @@
   describe 'attributes' do
     context 'with values' do
       it { is_expected.to have_attributes(**attributes) }
-      it { expect(subject.expandset).to eq(Set.new) }
+      it { expect(subject.expandset).to eq([]) }
       it { expect(subject.execution_deadline).to eq(0) }
       it { expect(subject.variables).to be_instance_of(Gitlab::Ci::Variables::Collection) }
       it { expect(subject.variables_hash).to be_instance_of(ActiveSupport::HashWithIndifferentAccess) }
@@ -25,11 +25,36 @@
       let(:attributes) { { project: nil, user: nil, sha: nil } }
 
       it { is_expected.to have_attributes(**attributes) }
-      it { expect(subject.expandset).to eq(Set.new) }
+      it { expect(subject.expandset).to eq([]) }
       it { expect(subject.execution_deadline).to eq(0) }
       it { expect(subject.variables).to be_instance_of(Gitlab::Ci::Variables::Collection) }
       it { expect(subject.variables_hash).to be_instance_of(ActiveSupport::HashWithIndifferentAccess) }
     end
+
+    context 'when FF ci_fix_max_includes is disabled' do
+      before do
+        stub_feature_flags(ci_fix_max_includes: false)
+      end
+
+      context 'with values' do
+        it { is_expected.to have_attributes(**attributes) }
+        it { expect(subject.expandset).to eq(Set.new) }
+        it { expect(subject.execution_deadline).to eq(0) }
+        it { expect(subject.variables).to be_instance_of(Gitlab::Ci::Variables::Collection) }
+        it { expect(subject.variables_hash).to be_instance_of(ActiveSupport::HashWithIndifferentAccess) }
+        it { expect(subject.variables_hash).to include('a' => 'b') }
+      end
+
+      context 'without values' do
+        let(:attributes) { { project: nil, user: nil, sha: nil } }
+
+        it { is_expected.to have_attributes(**attributes) }
+        it { expect(subject.expandset).to eq(Set.new) }
+        it { expect(subject.execution_deadline).to eq(0) }
+        it { expect(subject.variables).to be_instance_of(Gitlab::Ci::Variables::Collection) }
+        it { expect(subject.variables_hash).to be_instance_of(ActiveSupport::HashWithIndifferentAccess) }
+      end
+    end
   end
 
   describe '#set_deadline' do
diff --git a/spec/lib/gitlab/ci/config/external/mapper/verifier_spec.rb b/spec/lib/gitlab/ci/config/external/mapper/verifier_spec.rb
index 4303f279cacb0c4486225e5cc0113af732a6cf2e..e39a1c6786b767450dd5bbe651ee0f448ca4919e 100644
--- a/spec/lib/gitlab/ci/config/external/mapper/verifier_spec.rb
+++ b/spec/lib/gitlab/ci/config/external/mapper/verifier_spec.rb
@@ -58,121 +58,184 @@
   describe '#process' do
     subject(:process) { verifier.process(files) }
 
-    context 'when files are local' do
-      let(:files) do
-        [
-          Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file1.yml' }, context),
-          Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file2.yml' }, context),
-          Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file3.yml' }, context)
-        ]
-      end
+    shared_examples 'when FF ci_fix_max_includes is enabled' do
+      context 'when files are local' do
+        let(:files) do
+          [
+            Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file1.yml' }, context),
+            Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file2.yml' }, context),
+            Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file3.yml' }, context)
+          ]
+        end
 
-      it 'returns an array of file objects' do
-        expect(process.map(&:location)).to contain_exactly(
-          'myfolder/file1.yml', 'myfolder/file2.yml', 'myfolder/file3.yml'
-        )
-      end
+        it 'returns an array of file objects' do
+          expect(process.map(&:location)).to contain_exactly(
+            'myfolder/file1.yml', 'myfolder/file2.yml', 'myfolder/file3.yml'
+          )
+        end
 
-      it 'adds files to the expandset' do
-        expect { process }.to change { context.expandset.count }.by(3)
-      end
+        it 'adds files to the expandset' do
+          expect { process }.to change { context.expandset.count }.by(3)
+        end
+
+        it 'calls Gitaly only once for all files', :request_store do
+          # 1 for project.commit.id, 1 for the files
+          expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(2)
+        end
+
+        context 'when the FF ci_batch_request_for_local_and_project_includes is disabled' do
+          before do
+            stub_feature_flags(ci_batch_request_for_local_and_project_includes: false)
+          end
 
-      it 'calls Gitaly only once for all files', :request_store do
-        # 1 for project.commit.id, 1 for the files
-        expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(2)
+          it 'calls Gitaly for each file', :request_store do
+            # 1 for project.commit.id, 3 for the files
+            expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(4)
+          end
+        end
       end
 
-      context 'when the FF ci_batch_request_for_local_and_project_includes is disabled' do
-        before do
-          stub_feature_flags(ci_batch_request_for_local_and_project_includes: false)
+      context 'when files are project files' do
+        let_it_be(:included_project) { create(:project, :repository, namespace: project.namespace, creator: user) }
+
+        let(:files) do
+          [
+            Gitlab::Ci::Config::External::File::Project.new(
+              { file: 'myfolder/file1.yml', project: included_project.full_path }, context
+            ),
+            Gitlab::Ci::Config::External::File::Project.new(
+              { file: 'myfolder/file2.yml', project: included_project.full_path }, context
+            ),
+            Gitlab::Ci::Config::External::File::Project.new(
+              { file: 'myfolder/file3.yml', project: included_project.full_path }, context
+            )
+          ]
         end
 
-        it 'calls Gitaly for each file', :request_store do
-          # 1 for project.commit.id, 3 for the files
-          expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(4)
+        around(:all) do |example|
+          create_and_delete_files(included_project, project_files) do
+            example.run
+          end
         end
-      end
-    end
 
-    context 'when files are project files' do
-      let_it_be(:included_project) { create(:project, :repository, namespace: project.namespace, creator: user) }
-
-      let(:files) do
-        [
-          Gitlab::Ci::Config::External::File::Project.new(
-            { file: 'myfolder/file1.yml', project: included_project.full_path }, context
-          ),
-          Gitlab::Ci::Config::External::File::Project.new(
-            { file: 'myfolder/file2.yml', project: included_project.full_path }, context
-          ),
-          Gitlab::Ci::Config::External::File::Project.new(
-            { file: 'myfolder/file3.yml', project: included_project.full_path }, context
+        it 'returns an array of file objects' do
+          expect(process.map(&:location)).to contain_exactly(
+            'myfolder/file1.yml', 'myfolder/file2.yml', 'myfolder/file3.yml'
           )
-        ]
-      end
+        end
 
-      around(:all) do |example|
-        create_and_delete_files(included_project, project_files) do
-          example.run
+        it 'adds files to the expandset' do
+          expect { process }.to change { context.expandset.count }.by(3)
         end
-      end
 
-      it 'returns an array of file objects' do
-        expect(process.map(&:location)).to contain_exactly(
-          'myfolder/file1.yml', 'myfolder/file2.yml', 'myfolder/file3.yml'
-        )
-      end
+        it 'calls Gitaly only once for all files', :request_store do
+          # 1 for project.commit.id, 3 for the sha check, 1 for the files
+          expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(5)
+        end
+
+        context 'when the FF ci_batch_request_for_local_and_project_includes is disabled' do
+          before do
+            stub_feature_flags(ci_batch_request_for_local_and_project_includes: false)
+          end
 
-      it 'adds files to the expandset' do
-        expect { process }.to change { context.expandset.count }.by(3)
+          it 'calls Gitaly for each file', :request_store do
+            # 1 for project.commit.id, 3 for the sha check, 3 for the files
+            expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(7)
+          end
+        end
       end
 
-      it 'calls Gitaly only once for all files', :request_store do
-        # 1 for project.commit.id, 3 for the sha check, 1 for the files
-        expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(5)
+      context 'when a file includes other files' do
+        let(:files) do
+          [
+            Gitlab::Ci::Config::External::File::Local.new({ local: 'nested_configs.yml' }, context)
+          ]
+        end
+
+        it 'returns an array of file objects with combined hash' do
+          expect(process.map(&:to_hash)).to contain_exactly(
+            { my_build: { script: 'echo Hello World' },
+              my_test: { script: 'echo Hello World' },
+              remote_test: { script: 'echo Hello World' } }
+          )
+        end
       end
 
-      context 'when the FF ci_batch_request_for_local_and_project_includes is disabled' do
-        before do
-          stub_feature_flags(ci_batch_request_for_local_and_project_includes: false)
+      context 'when there is an invalid file' do
+        let(:files) do
+          [
+            Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/invalid.yml' }, context)
+          ]
         end
 
-        it 'calls Gitaly for each file', :request_store do
-          # 1 for project.commit.id, 3 for the sha check, 3 for the files
-          expect { process }.to change { Gitlab::GitalyClient.get_request_count }.by(7)
+        it 'adds an error to the file' do
+          expect(process.first.errors).to include("Local file `myfolder/invalid.yml` does not exist!")
         end
       end
     end
 
-    context 'when a file includes other files' do
-      let(:files) do
-        [
-          Gitlab::Ci::Config::External::File::Local.new({ local: 'nested_configs.yml' }, context)
-        ]
+    it_behaves_like 'when FF ci_fix_max_includes is enabled'
+
+    context 'when FF ci_fix_max_includes is disabled' do
+      before do
+        stub_feature_flags(ci_fix_max_includes: false)
       end
 
-      it 'returns an array of file objects with combined hash' do
-        expect(process.map(&:to_hash)).to contain_exactly(
-          { my_build: { script: 'echo Hello World' },
-            my_test: { script: 'echo Hello World' },
-            remote_test: { script: 'echo Hello World' } }
-        )
+      it_behaves_like 'when FF ci_fix_max_includes is enabled'
+
+      context 'when max_includes is exceeded' do
+        context 'when files are nested' do
+          let(:files) do
+            [
+              Gitlab::Ci::Config::External::File::Local.new({ local: 'nested_configs.yml' }, context)
+            ]
+          end
+
+          before do
+            allow(context).to receive(:max_includes).and_return(1)
+          end
+
+          it 'raises Processor::IncludeError' do
+            expect { process }.to raise_error(Gitlab::Ci::Config::External::Processor::IncludeError)
+          end
+        end
+
+        context 'when files are not nested' do
+          let(:files) do
+            [
+              Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file1.yml' }, context),
+              Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/file2.yml' }, context)
+            ]
+          end
+
+          before do
+            allow(context).to receive(:max_includes).and_return(1)
+          end
+
+          it 'raises Mapper::TooManyIncludesError' do
+            expect { process }.to raise_error(Gitlab::Ci::Config::External::Mapper::TooManyIncludesError)
+          end
+        end
       end
     end
 
-    context 'when there is an invalid file' do
-      let(:files) do
-        [
-          Gitlab::Ci::Config::External::File::Local.new({ local: 'myfolder/invalid.yml' }, context)
-        ]
-      end
+    describe 'max includes detection' do
+      shared_examples 'when total file count is equal to max_includes' do
+        before do
+          allow(context).to receive(:max_includes).and_return(expected_total_file_count)
+        end
+
+        it 'adds the expected number of files to expandset' do
+          process
 
-      it 'adds an error to the file' do
-        expect(process.first.errors).to include("Local file `myfolder/invalid.yml` does not exist!")
+          expect(context.expandset.count).to eq(expected_total_file_count)
+        end
+
+        it 'does not raise an error' do
+          expect { process }.not_to raise_error
+        end
       end
-    end
 
-    context 'when max_includes is exceeded' do
       context 'when files are nested' do
         let(:files) do
           [
@@ -180,13 +243,19 @@
           ]
         end
 
-        before do
-          allow(context).to receive(:max_includes).and_return(1)
-        end
+        let(:expected_total_file_count) { 4 }
 
-        it 'raises Processor::IncludeError' do
-          expect { process }.to raise_error(Gitlab::Ci::Config::External::Processor::IncludeError)
+        context 'when total file count exceeds max_includes' do
+          before do
+            allow(context).to receive(:max_includes).and_return(expected_total_file_count - 1)
+          end
+
+          it 'raises Processor::IncludeError' do
+            expect { process }.to raise_error(Gitlab::Ci::Config::External::Processor::IncludeError)
+          end
         end
+
+        it_behaves_like 'when total file count is equal to max_includes'
       end
 
       context 'when files are not nested' do
@@ -197,13 +266,19 @@
           ]
         end
 
-        before do
-          allow(context).to receive(:max_includes).and_return(1)
-        end
+        let(:expected_total_file_count) { files.count }
 
-        it 'raises Mapper::TooManyIncludesError' do
-          expect { process }.to raise_error(Gitlab::Ci::Config::External::Mapper::TooManyIncludesError)
+        context 'when total file count exceeds max_includes' do
+          before do
+            allow(context).to receive(:max_includes).and_return(expected_total_file_count - 1)
+          end
+
+          it 'raises Mapper::TooManyIncludesError' do
+            expect { process }.to raise_error(Gitlab::Ci::Config::External::Mapper::TooManyIncludesError)
+          end
         end
+
+        it_behaves_like 'when total file count is equal to max_includes'
       end
     end
   end
diff --git a/spec/lib/gitlab/ci/config/external/mapper_spec.rb b/spec/lib/gitlab/ci/config/external/mapper_spec.rb
index a053c3047de2f1405955a19f794bcf94e236447d..bc05ac380deab16fb7a397738f2f1ed53a332b1d 100644
--- a/spec/lib/gitlab/ci/config/external/mapper_spec.rb
+++ b/spec/lib/gitlab/ci/config/external/mapper_spec.rb
@@ -236,9 +236,20 @@
         expect { process }.not_to raise_error
       end
 
-      it 'has expanset with one' do
+      it 'has expanset with two' do
         process
-        expect(context.expandset.size).to eq(1)
+        expect(context.expandset.size).to eq(2)
+      end
+
+      context 'when FF ci_fix_max_includes is disabled' do
+        before do
+          stub_feature_flags(ci_fix_max_includes: false)
+        end
+
+        it 'has expanset with one' do
+          process
+          expect(context.expandset.size).to eq(1)
+        end
       end
     end