diff --git a/pkgs/development/ocaml-modules/processor/default.nix b/pkgs/development/ocaml-modules/processor/default.nix
index 4a914449251a..d4eba003ea67 100644
--- a/pkgs/development/ocaml-modules/processor/default.nix
+++ b/pkgs/development/ocaml-modules/processor/default.nix
@@ -6,15 +6,15 @@
 
 buildDunePackage rec {
   pname = "processor";
-  version = "0.1";
+  version = "0.1-unstable-2024-07-23";
 
   minimalOCamlVersion = "4.08";
 
   src = fetchFromGitHub {
     owner = "haesbaert";
     repo = "ocaml-processor";
-    tag = "v${version}";
-    hash = "sha256-eGSNYjVbUIUMelajqZYOd3gvmRKQ9UP3TfMflLR9i7k=";
+    rev = "74df5ab38773e5c4ad5c3a3f21f525d863731c17";
+    hash = "sha256-tWmgAsYfcpZUyxo7F+WIC3WOfAjDiuV74CscqEd93gk=";
   };
 
   doCheck = true;