diff --git a/pkgs/games/otto-matic/default.nix b/pkgs/games/otto-matic/default.nix
index c56db251a1b0..6d0633febbd2 100644
--- a/pkgs/games/otto-matic/default.nix
+++ b/pkgs/games/otto-matic/default.nix
@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "OttoMatic";
-  version = "4.0.1";
+  version = "unstable-2023-11-13";
 
   src = fetchFromGitHub {
     owner = "jorio";
     repo = pname;
-    rev = version;
-    sha256 = "sha256-0mqOAdAmJGxKa6yXktrbmdXkoQIliimq37iy9bCBZYg=";
+    rev = "8a5411779762684066d3748fbf4d33747ca871a4";
+    hash = "sha256-cZ2gHNXmjMocfTgbA+0T2nwKs55ZMDoB+JTf0Qdqe8U=";
     fetchSubmodules = true;
   };
 
@@ -40,5 +40,6 @@ stdenv.mkDerivation rec {
     license = licenses.cc-by-sa-40;
     maintainers = with maintainers; [ lux ];
     platforms = platforms.linux;
+    mainProgram = "OttoMatic";
   };
 }