diff --git a/lib/rubocop/cop/documentation.rb b/lib/rubocop/cop/documentation.rb
index 651bcde37c9..28e3262f43a 100644
--- a/lib/rubocop/cop/documentation.rb
+++ b/lib/rubocop/cop/documentation.rb
@@ -8,7 +8,7 @@ module Documentation
 
       # @api private
       def department_to_basename(department)
-        "cops_#{department.downcase}"
+        "cops_#{department.to_s.downcase.tr('/', '_')}"
       end
 
       # @api private