diff --git a/pkgs/misc/documentation-highlighter/default.nix b/pkgs/misc/documentation-highlighter/default.nix
index 2a34e36742d5..22ea3a5f86e3 100644
--- a/pkgs/misc/documentation-highlighter/default.nix
+++ b/pkgs/misc/documentation-highlighter/default.nix
@@ -7,6 +7,16 @@ runCommand "documentation-highlighter" {
     platforms = lib.platforms.all;
     maintainers = [ lib.maintainers.grahamc ];
   };
+  src = lib.sources.cleanSourceWith {
+    src = ./.;
+    filter = path: type: lib.elem path (map toString [
+      ./highlight.pack.js
+      ./LICENSE
+      ./loader.js
+      ./mono-blue.css
+      ./README.md
+    ]);
+  };
 } ''
-  cp -r ${./.} $out
+  cp -r "$src" "$out"
 ''