diff --git a/docs/dune b/docs/dune
index 045c9e1..cbd381c 100644
--- a/docs/dune
+++ b/docs/dune
@@ -24,7 +24,9 @@
   (source_tree assets)
   (source_tree trees))
  (action
-  (run ./forester_docs.exe)))
+  (progn
+   (run rm -rf output)
+   (run ./forester_docs.exe))))
 
 (install
  (section