diff --git a/pkgs/development/python-modules/nix-prefetch-github/default.nix b/pkgs/development/python-modules/nix-prefetch-github/default.nix
index ae1d3c35eac2..d4aed2d8de0d 100644
--- a/pkgs/development/python-modules/nix-prefetch-github/default.nix
+++ b/pkgs/development/python-modules/nix-prefetch-github/default.nix
@@ -47,7 +47,7 @@ buildPythonPackage rec {
   sphinxRoot = "docs";
 
   # ignore tests which are impure
-  DISABLED_TESTS = "network requires_nix_build";
+  env.DISABLED_TESTS = "network requires_nix_build";
 
   meta = {
     description = "Prefetch sources from github";