diff --git a/lib/active_storage/service/custom_s3_service.rb b/lib/active_storage/service/custom_s3_service.rb
index ab32f14e8..53e5a2e04 100644
--- a/lib/active_storage/service/custom_s3_service.rb
+++ b/lib/active_storage/service/custom_s3_service.rb
@@ -18,6 +18,10 @@ module ActiveStorage
       end
     end
 
+    def path_for(key)
+      subfolder.present? ? File.join(subfolder, key) : key
+    end
+
     private
 
     def object_for(key)