diff --git a/pkgs/by-name/ph/physac/package.nix b/pkgs/by-name/ph/physac/package.nix
index 3040c9eda253..5d6ff694e5ab 100644
--- a/pkgs/by-name/ph/physac/package.nix
+++ b/pkgs/by-name/ph/physac/package.nix
@@ -6,7 +6,7 @@
 
 stdenvNoCC.mkDerivation (finalAttrs: {
   pname = "physac";
-  version = "2.5-unstable-2023-12-11";
+  version = "1.1-unstable-2023-12-11";
 
   src = fetchFromGitHub {
     owner = "victorfisac";