diff --git a/ci/niv-cron.nix b/ci/niv-cron.nix
index 652d504b..c1bd3aab 100644
--- a/ci/niv-cron.nix
+++ b/ci/niv-cron.nix
@@ -29,10 +29,11 @@ with lib; {
             chmod 0600 ~/.ssh/id_rsa
             for source in ${toString (attrNames sources)}; do
               if nix run -f . pkgs.niv  -c niv update $source; then
-                echo $(nix eval --raw "(import ./.).sources.$source.outPath") | ${cachix}/bin/cachix push kittywitch
+              ${cachix}/bin/cachix push kittywitch $(nix eval --raw "(import ./.).sources.$source.outPath")
               fi
             done
-            cachix push kittywitch $(nix eval --raw -f ../. sourceCache)
+            nix build -f ../. sourceCache
+            ${cachix}/bin/cachix push kittywitch $(nix eval '(toString (import ../.).sourceCache)')
             if git status --porcelain | grep -qF nix/sources.json; then
               if nix build -Lf . hosts.{athame,yule,samhain}.config.system.build.toplevel; then
                 git add nix/sources.json
diff --git a/default.nix b/default.nix
index 5678a5be..16a3efe1 100644
--- a/default.nix
+++ b/default.nix
@@ -19,7 +19,7 @@ rec {
 
     runners = import ./runners.nix { inherit lib; inherit (deploy) target; };
 
-  sourceCache = toString (lib.mapAttrsToList(sourceName: value: value.outPath) (removeAttrs (import sources.nix-hexchen {}).sources [ "__functor" ]));
+    sourceCache = lib.mapAttrsToList(sourceName: value: if lib.isDerivation value.outPath then value.outPath else value) (removeAttrs (import sources.nix-hexchen {}).sources [ "__functor" ]);
 
   deploy = import ./lib/deploy.nix {
     inherit pkgs sources;