diff --git a/flake.nix b/flake.nix
index 001373ee7afc960ce925bda186a828a0a02bc51b..6b6cab8e4e8be163ceb401286b965aef000da85e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -47,7 +47,7 @@
         .haskellPackages;
     in rec {
       packages = {
-        default = hpkgs.rtree;
+        default = hpkgs.rtree-c;
         rtree = hpkgs.rtree;
         rtree-c = hpkgs.rtree-c;
       };