diff --git a/corepkgs/unpack-channel.nix b/corepkgs/unpack-channel.nix
index 170f3ab07c..0fc2b2f456 100644
--- a/corepkgs/unpack-channel.nix
+++ b/corepkgs/unpack-channel.nix
@@ -8,4 +8,6 @@ derivation {
   args = [ "-e" ./unpack-channel.sh ];
   inherit name channelName src bzip2 tar tr;
   PATH = "${nixBinDir}:${coreutils}";
+  # No point in doing this remotely.
+  preferLocalBuild = true;
 }