diff --git a/CHANGES.md b/CHANGES.md
index 91c0f6e..c624f65 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,7 @@
+v0.4.1 (27th September 2022)
+----------------------------
+Bugfix for integer shift counts
+
 v0.4 (23rd September 2022)
 --------------------------
 
diff --git a/malfunction.opam b/malfunction.opam
index ba98852..851e2a3 100644
--- a/malfunction.opam
+++ b/malfunction.opam
@@ -12,8 +12,8 @@ build: [
 depends: [
   "ocaml" {>= "4.04" & < "5.0.0"}
   "ocamlfind"
-  "dune"
-  "cppo" {build}
+  "dune" {>= "1.2"}
+  "cppo" {build & >= "1.1.0"}
   "omd" {with-test & < "2.0.0~"}
   "craml" {with-test}
   "zarith"