diff --git a/pkgs/development/python-modules/rctclient/default.nix b/pkgs/development/python-modules/rctclient/default.nix
index effc8f73d0fb..488ad68e7c1b 100644
--- a/pkgs/development/python-modules/rctclient/default.nix
+++ b/pkgs/development/python-modules/rctclient/default.nix
@@ -7,7 +7,7 @@
   pytestCheckHook,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "rctclient";
   version = "0.0.5";
   pyproject = true;
@@ -15,7 +15,7 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "svalouch";
     repo = "python-rctclient";
-    tag = "v${version}";
+    tag = "v${finalAttrs.version}";
     hash = "sha256-f85ETzuZpOgnWpiLipLtAjOPn63yniCffWdPLyCEC3w=";
   };
 
@@ -30,8 +30,8 @@ buildPythonPackage rec {
   meta = {
     description = "Python implementation of the RCT Power GmbH Serial Communication Protocol";
     homepage = "https://github.com/svalouch/python-rctclient";
-    changelog = "https://github.com/svalouch/python-rctclient/releases/tag/${src.tag}";
-    license = with lib.licenses; [ gpl3Only ];
+    changelog = "https://github.com/svalouch/python-rctclient/releases/tag/${finalAttrs.src.tag}";
+    license = lib.licenses.gpl3Only;
     maintainers = with lib.maintainers; [ _9R ];
   };
-}
+})