diff --git a/nix/default.nix b/nix/default.nix
index 5dfa42c8..ce6da3fe 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -70,7 +70,7 @@ in stdenv.mkDerivation rec {
     "V=${toString verbosity}"
     "QUICK_AND_DIRTY_COMPILER=${if quickAndDirty then "1" else "0"}"
     "QUICK_AND_DIRTY_NIMBLE=${if quickAndDirty then "1" else "0"}"
-    "TARGET_OS=${if stdenv.hostPlatform.isDarwin then "macOS" else "Linux"}"
+    "TARGET_OS=${if stdenv.isDarwin then "macOS" else "Linux"}"
   ];
 
   # FIXME: Remove once permanent fix is applied to NBS: