diff --git a/pkgs/os-specific/linux/mdadm/default.nix b/pkgs/os-specific/linux/mdadm/default.nix
index dc1697b9e9b..465dc58199e 100644
--- a/pkgs/os-specific/linux/mdadm/default.nix
+++ b/pkgs/os-specific/linux/mdadm/default.nix
@@ -1,5 +1,7 @@
 { stdenv, fetchurl, groff }:
 
+assert stdenv.isLinux;
+
 stdenv.mkDerivation rec {
   name = "mdadm-3.3.4";