diff --git a/CHANGES.md b/CHANGES.md
index 101ef2d..82530cd 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,8 @@
+2.13.1 (Pending)
+----------------
+
+* Fix unavailable expunge on Windows (#447, @jonahbeckford)
+
 2.13.0 (2023-07-03)
 -------------------
 
diff --git a/src/top/dune b/src/top/dune
index f94d184..6549316 100644
--- a/src/top/dune
+++ b/src/top/dune
@@ -33,7 +33,7 @@
 (rule
  (targets utop-expunged.bc)
  (action
-  (run %{ocaml_where}/expunge %{dep:utop.bc} %{targets}
+  (run %{ocaml_where}/expunge%{ext_exe} %{dep:utop.bc} %{targets}
     %{read-lines:modules.txt})))
 
 (install