diff --git a/third_party/gn/webgpu-cts/BUILD.gn b/third_party/gn/webgpu-cts/BUILD.gn
index f9f71cb..e0a77a2 100644
--- a/third_party/gn/webgpu-cts/BUILD.gn
+++ b/third_party/gn/webgpu-cts/BUILD.gn
@@ -109,11 +109,11 @@
   script = "${dawn_root}/webgpu-cts/scripts/copy_files.py"
   args = [
     "--src_dir",
-    rebase_path(src_dir),
+    rebase_path(src_dir, root_build_dir),
     "--dst_dir",
-    rebase_path(dst_dir),
+    rebase_path(dst_dir, root_build_dir),
     "--file_list",
-    rebase_path("resource_files.txt"),
+    rebase_path("resource_files.txt", root_build_dir),
     "--stamp",
     rebase_path(outputs[0], root_build_dir),
   ]