diff --git a/pkgs/development/python-modules/opower/default.nix b/pkgs/development/python-modules/opower/default.nix
index 3db927745be7..dbdb3cf9df5a 100644
--- a/pkgs/development/python-modules/opower/default.nix
+++ b/pkgs/development/python-modules/opower/default.nix
@@ -13,7 +13,7 @@
   setuptools,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "opower";
   version = "0.16.1";
   pyproject = true;
@@ -21,7 +21,7 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "tronikos";
     repo = "opower";
-    tag = "v${version}";
+    tag = "v${finalAttrs.version}";
     hash = "sha256-+Jpse32N1D697jQnutEPvdcL/AmE0ntO1IGyG3qHN1w=";
   };
 
@@ -56,8 +56,8 @@ buildPythonPackage rec {
   meta = {
     description = "Module for getting historical and forecasted usage/cost from utilities that use opower.com";
     homepage = "https://github.com/tronikos/opower";
-    changelog = "https://github.com/tronikos/opower/releases/tag/${src.tag}";
+    changelog = "https://github.com/tronikos/opower/releases/tag/${finalAttrs.src.tag}";
     license = lib.licenses.asl20;
     maintainers = with lib.maintainers; [ fab ];
   };
-}
+})