diff --git a/pkgs/development/python-modules/pymc/default.nix b/pkgs/development/python-modules/pymc/default.nix
index 25246c401066..61abe51f042a 100644
--- a/pkgs/development/python-modules/pymc/default.nix
+++ b/pkgs/development/python-modules/pymc/default.nix
@@ -23,14 +23,14 @@
 
 buildPythonPackage (finalAttrs: {
   pname = "pymc";
-  version = "5.28.3";
+  version = "5.28.4";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "pymc-devs";
     repo = "pymc";
     tag = "v${finalAttrs.version}";
-    hash = "sha256-4RFLtIlAlLvOZ4xRvwnbMNEfHUdjsUDPn3CawyTEXQU=";
+    hash = "sha256-REQ9+II6MFZ64FlJudRRhmXA4/Cb017XrsrZFZBY7R0=";
   };
 
   build-system = [