diff --git a/src/dune b/src/dune
index a9322eed..4d89c12f 100644
--- a/src/dune
+++ b/src/dune
@@ -37,8 +37,16 @@
 (rule
  (target assets_crunch.ml)
  (deps
-  (source_tree ../assets))
+  (source_tree ../assets)
+  (source_tree ../default/assets)
+  )
  (action
   (with-stdout-to
    %{null}
    (run ocaml-crunch -m plain ../assets -o %{target}))))
+
+(rule
+ (action
+  (progn
+   (run sh -c "test -d ../assets || cp -r ../default/assets ../assets")))
+ (sandbox none))