diff --git a/flake.nix b/flake.nix
index 62d4d11bf..8157f2177 100644
--- a/flake.nix
+++ b/flake.nix
@@ -110,7 +110,7 @@
       devShell.x86_64-linux = packages.x86_64-linux.nac3artiq;
 
       # Use "nix shell" to enter a development environment.
-      defaultPackage.x86_64-linux = pkgs.buildEnv {
+      defaultPackage.x86_64-linux = pkgs.buildEnv rec {
         name = "nac3-dev-shell";
         paths = with pkgs; [
           llvm_12
@@ -124,12 +124,13 @@
           clippy
           (python3.withPackages(ps: [ ps.numpy ]))
         ];
+        passthru.hydrapkgs = paths;
       };
 
       hydraJobs = {
         inherit (packages.x86_64-linux) nac3artiq;
         nac3artiq-mingw = packages.x86_64-w64-mingw32.nac3artiq;
-      } // (pkgs.lib.foldr (a: b: {"${pkgs.lib.strings.getName a}" = a;} // b) {} defaultPackage.x86_64-linux.paths);
+      } // (pkgs.lib.foldr (a: b: {"${pkgs.lib.strings.getName a}" = a;} // b) {} defaultPackage.x86_64-linux.hydrapkgs);
   };
 
   nixConfig = {