diff --git a/installer.nix b/installer.nix
index cbd2ba5..ba59526 100644
--- a/installer.nix
+++ b/installer.nix
@@ -28,8 +28,10 @@ nixpkgs: machine:
 
         isoImage = {
           compressImage = false;
-          squashfsCompression = "gzip -Xcompression-level 1";
+          squashfsCompression = "lz4";
           isoName = lib.mkForce "installer.iso";
+          ## ^^ FIXME: Use a more interesting name or keep the default name and
+          ## use `isoImage.isoName` in the tests.
         };
       };
   in