diff --git a/lib/tasks/assets.rake b/lib/tasks/assets.rake
index d10fd89779..9288fa499e 100644
--- a/lib/tasks/assets.rake
+++ b/lib/tasks/assets.rake
@@ -109,7 +109,7 @@ def compress_node(from, to)
   assets = cdn_relative_path("/assets")
   assets_additional_path = (d = File.dirname(from)) == "." ? "" : "/#{d}"
   source_map_root = assets + assets_additional_path
-  source_map_url = cdn_path "/assets/#{to}.map"
+  source_map_url = "#{File.basename(to)}.map"
   base_source_map = assets_path + assets_additional_path
 
   cmd = <<~EOS