diff --git a/flake.nix b/flake.nix
index be9a938..afcb025 100644
--- a/flake.nix
+++ b/flake.nix
@@ -104,10 +104,24 @@
         platforms = lib.platforms.all;
       };
 
-      src = lib.cleanSource ./.;
+      src = builtins.filterSource (path: type: let
+        baseName = baseNameOf (toString path);
+      in !(lib.any (b: b) [
+          (!(lib.cleanSourceFilter path type))
+          (baseName == ".github" && type == "directory")
+          (baseName == "nix" && type == "directory")
+          (baseName == ".envrc" && type == "regular")
+          (baseName == "flake.lock" && type == "regular")
+          (baseName == "flake.nix" && type == "regular")
+        ])) ./.;
+
     in forAllSystems (system: pkgs: {
       default = self.packages.${system}.database;
 
+      filteredSource = pkgs.runCommandLocal "filtered-source" { } ''
+        ln -s ${src} $out
+      '';
+
       jmdict = pkgs.callPackage ./nix/jmdict.nix {
           inherit jmdict-src jmdict-with-examples-src edrdgMetadata;
       };