diff --git a/ofborg/src/tasks/eval/nixpkgs.rs b/ofborg/src/tasks/eval/nixpkgs.rs
index 7b0edaf..833f42d 100644
--- a/ofborg/src/tasks/eval/nixpkgs.rs
+++ b/ofborg/src/tasks/eval/nixpkgs.rs
@@ -529,6 +529,9 @@ impl<'a> EvaluationStrategy for NixpkgsStrategy<'a> {
                     String::from("--arg"),
                     String::from("nixpkgs"),
                     nixpkgs_arg_value.clone(),
+                    String::from("--arg"),
+                    String::from("config"),
+                    String::from("{ allowAliases = false; }"),
                     String::from("./pkgs/top-level/release.nix"),
                     String::from("-A"),
                     String::from("tarball"),