diff --git a/scripts/build-art.ts b/scripts/build-art.ts
index fe8a375..a3350b5 100644
--- a/scripts/build-art.ts
+++ b/scripts/build-art.ts
@@ -9,14 +9,17 @@
  */
 
 import { readFileSync, writeFileSync } from "fs";
-import { join } from "path";
+import { join, dirname } from "path";
+import { fileURLToPath } from "url";
 import { ANIMAL_ART } from "../server/art.ts";
 import { ANIMALS, ANIMAL_COLOR } from "../server/engine.ts";
 import { ART_META } from "../server/art-meta.ts";
 import type { AnimalId } from "../server/engine.ts";
 
-// Resolve paths relative to this script's directory
-const SCRIPT_DIR = new URL(".", import.meta.url).pathname;
+// Resolve paths relative to this script's directory.
+// fileURLToPath gives a proper platform path; `new URL(...).pathname` returns
+// "/C:/..." on Windows which breaks downstream join() calls.
+const SCRIPT_DIR = dirname(fileURLToPath(import.meta.url));
 const PROJECT_ROOT = join(SCRIPT_DIR, "..");
 const SHELL_PATH = join(PROJECT_ROOT, "statusline", "pet-status.sh");