diff --git a/pkgs/development/python-modules/fastcore/default.nix b/pkgs/development/python-modules/fastcore/default.nix
index 814d257fa233..059ab8d4dbc3 100644
--- a/pkgs/development/python-modules/fastcore/default.nix
+++ b/pkgs/development/python-modules/fastcore/default.nix
@@ -6,7 +6,7 @@
   setuptools,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "fastcore";
   version = "1.12.2";
   pyproject = true;
@@ -14,7 +14,7 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "fastai";
     repo = "fastcore";
-    tag = version;
+    tag = finalAttrs.version;
     hash = "sha256-6nEHriXEQjovcDY9jh/QkwiQc2Wdq/87Nxfa+AhrPj4=";
   };
 
@@ -30,8 +30,8 @@ buildPythonPackage rec {
   meta = {
     description = "Python module for Fast AI";
     homepage = "https://github.com/fastai/fastcore";
-    changelog = "https://github.com/fastai/fastcore/blob/${src.tag}/CHANGELOG.md";
-    license = with lib.licenses; [ asl20 ];
+    changelog = "https://github.com/fastai/fastcore/blob/${finalAttrs.src.tag}/CHANGELOG.md";
+    license = lib.licenses.asl20;
     maintainers = with lib.maintainers; [ fab ];
   };
-}
+})