diff --git a/lib/rubocop/cop/internal_affairs/undefined_config.rb b/lib/rubocop/cop/internal_affairs/undefined_config.rb
index bb248c80c4bb1..1e44dd49c8d0e 100644
--- a/lib/rubocop/cop/internal_affairs/undefined_config.rb
+++ b/lib/rubocop/cop/internal_affairs/undefined_config.rb
@@ -5,12 +5,21 @@ module Cop
     module InternalAffairs
       # Looks for references to a cop configuration key that isn't defined in config/default.yml.
       class UndefinedConfig < Base
+        # FileFinder is private API not expected to be used by cops but its fine for InternalAffairs
+        extend FileFinder
+
         ALLOWED_CONFIGURATIONS = %w[
           Safe SafeAutoCorrect AutoCorrect Severity StyleGuide Details Reference Include Exclude
         ].freeze
         RESTRICT_ON_SEND = %i[[] fetch].freeze
         MSG = '`%<name>s` is not defined in the configuration for `%<cop>s` ' \
               'in `config/default.yml`.'
+        CONFIG_PATH = find_file_upwards('config/default.yml', Dir.pwd)
+        CONFIG = if CONFIG_PATH
+                   ConfigLoader.load_yaml_configuration(CONFIG_PATH)
+                 else
+                   {}
+                 end
 
         # @!method cop_class_def(node)
         def_node_search :cop_class_def, <<~PATTERN
@@ -31,7 +40,7 @@ def on_new_investigation
           cop_class = cop_class_def(processed_source.ast).first
           return unless (@cop_class_name = extract_cop_name(cop_class))
 
-          @config_for_cop = RuboCop::ConfigLoader.default_configuration.for_cop(@cop_class_name)
+          @config_for_cop = CONFIG[@cop_class_name] || {}
         end
 
         def on_send(node)
diff --git a/spec/rubocop/cop/internal_affairs/undefined_config_spec.rb b/spec/rubocop/cop/internal_affairs/undefined_config_spec.rb
index 210b6a0a85a69..6caf43842e603 100644
--- a/spec/rubocop/cop/internal_affairs/undefined_config_spec.rb
+++ b/spec/rubocop/cop/internal_affairs/undefined_config_spec.rb
@@ -12,9 +12,8 @@
         Defined: true
     YAML
 
-    allow(RuboCop::ConfigLoader).to receive(:default_configuration).and_return(
-      RuboCop::ConfigLoader.load_file('config/default.yml', check: false)
-    )
+    stub_const('RuboCop::Cop::InternalAffairs::UndefinedConfig::CONFIG',
+               RuboCop::ConfigLoader.load_yaml_configuration('config/default.yml'))
   end
 
   it 'does not register an offense for implicit configuration keys' do
diff --git a/spec/rubocop/file_finder_spec.rb b/spec/rubocop/file_finder_spec.rb
index 465d29f9a1228..42c4de5ebcb0a 100644
--- a/spec/rubocop/file_finder_spec.rb
+++ b/spec/rubocop/file_finder_spec.rb
@@ -19,6 +19,16 @@
     it 'returns nil when file is not found' do
       expect(finder.find_file_upwards('file2', 'dir')).to be_nil
     end
+
+    context 'when searching for a file inside a directory' do
+      it 'returns a file to be found upwards' do
+        expect(finder.find_file_upwards('dir/file', Dir.pwd)).to eq(File.expand_path('file', 'dir'))
+      end
+
+      it 'returns nil when file is not found' do
+        expect(finder.find_file_upwards('dir2/file', Dir.pwd)).to be_nil
+      end
+    end
   end
 
   describe '#find_last_file_upwards' do