diff --git a/pkgs/development/python-modules/model-checker/default.nix b/pkgs/development/python-modules/model-checker/default.nix
index 57f2a68db179..9be4f6cdf8f6 100644
--- a/pkgs/development/python-modules/model-checker/default.nix
+++ b/pkgs/development/python-modules/model-checker/default.nix
@@ -11,7 +11,7 @@
 
 buildPythonPackage rec {
   pname = "model-checker";
-  version = "1.0.2";
+  version = "1.2.3";
   pyproject = true;
 
   disabled = pythonOlder "3.8";
@@ -19,7 +19,7 @@ buildPythonPackage rec {
   src = fetchPypi {
     pname = "model_checker";
     inherit version;
-    hash = "sha256-oNJ9GkkxbvpEoNl60T44qNy+vsZ4d62iUikZowr1ZNI=";
+    hash = "sha256-LB5Smv8m+lWOV+cA7MvRfG8dI9fJgOCK9Rn2GgRYjtQ=";
   };
 
   # z3 does not provide a dist-info, so python-runtime-deps-check will fail