diff --git a/pkgs/development/python-modules/smp/default.nix b/pkgs/development/python-modules/smp/default.nix
index 548e087ab316..9f4e65e45917 100644
--- a/pkgs/development/python-modules/smp/default.nix
+++ b/pkgs/development/python-modules/smp/default.nix
@@ -7,6 +7,7 @@
   crcmod,
   eval-type-backport,
   pydantic,
+  pyprojectVersionPatchHook,
   pytestCheckHook,
 }:
 
@@ -22,10 +23,9 @@ buildPythonPackage rec {
     hash = "sha256-RjecTnMYNcJeD7wqq4FkwRvEgTn5V/RwMfOjf2dqQ+U=";
   };
 
-  postPatch = ''
-    substituteInPlace pyproject.toml \
-      --replace-fail 'version = "0"' 'version = "${version}"'
-  '';
+  nativeBuildInputs = [
+    pyprojectVersionPatchHook
+  ];
 
   build-system = [
     poetry-core
@@ -38,6 +38,10 @@ buildPythonPackage rec {
     pydantic
   ];
 
+  pythonRelaxDeps = [
+    "cbor2"
+  ];
+
   nativeCheckInputs = [
     pytestCheckHook
   ];