diff --git a/pkgs/development/python-modules/prometheus-fastapi-instrumentator/default.nix b/pkgs/development/python-modules/prometheus-fastapi-instrumentator/default.nix
index 25555998ed24..06867352d6ec 100644
--- a/pkgs/development/python-modules/prometheus-fastapi-instrumentator/default.nix
+++ b/pkgs/development/python-modules/prometheus-fastapi-instrumentator/default.nix
@@ -13,7 +13,7 @@
   starlette,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "prometheus-fastapi-instrumentator";
   version = "7.1.0";
   pyproject = true;
@@ -21,7 +21,7 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "trallnag";
     repo = "prometheus-fastapi-instrumentator";
-    tag = "v${version}";
+    tag = "v${finalAttrs.version}";
     hash = "sha256-54h/kwIdzFzxdYglwcEBPkLYno1YH2iWklg35qY2b00=";
   };
 
@@ -50,7 +50,7 @@ buildPythonPackage rec {
   meta = {
     description = "Instrument FastAPI with Prometheus metrics";
     homepage = "https://github.com/trallnag/prometheus-fastapi-instrumentator";
-    changelog = "https://github.com/trallnag/prometheus-fastapi-instrumentator/blob/${src.tag}/CHANGELOG.md";
+    changelog = "https://github.com/trallnag/prometheus-fastapi-instrumentator/blob/${finalAttrs.src.tag}/CHANGELOG.md";
     license = with lib.licenses; [
       isc
       bsd3
@@ -58,4 +58,4 @@ buildPythonPackage rec {
     maintainers = with lib.maintainers; [ bcdarwin ];
     platforms = lib.platforms.unix;
   };
-}
+})