diff --git a/src/dune b/src/dune
index e72c404..48704e8 100644
--- a/src/dune
+++ b/src/dune
@@ -9,6 +9,7 @@
   (pps ppx_js_style -check-doc-comments))
  (preprocess
   (pps
+   -unused-code-warnings=force
    ppx_compare
    ppx_enumerate
    ppx_hash
diff --git a/test/dune b/test/dune
index 0cc2d63..77822aa 100644
--- a/test/dune
+++ b/test/dune
@@ -20,6 +20,7 @@
   (pps ppx_js_style -check-doc-comments))
  (preprocess
   (pps
+   -unused-code-warnings=force
    ppx_compare
    ppx_enumerate
    ppx_expect