diff --git a/pkgs/development/tools/misc/hydra/default.nix b/pkgs/development/tools/misc/hydra/default.nix
index 395ab5349c2..00f679cfdac 100644
--- a/pkgs/development/tools/misc/hydra/default.nix
+++ b/pkgs/development/tools/misc/hydra/default.nix
@@ -8,6 +8,10 @@
 
 with stdenv;
 
+if lib.versions.major nix.version == "1"
+  then throw "This Hydra version doesn't support Nix 1.x"
+else
+
 let
   isGreaterNix20 = with lib.versions;
     let