diff --git a/astro.config.mjs b/astro.config.mjs
index 5b5267d..93a9357 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -66,6 +66,16 @@ export default defineConfig({
     dangerouslyProcessSVG: true,
   },
   vite: {
+    // Pre-bundle the analytics tracker during dev server startup. It is only
+    // referenced from a client `<script>`, so Vite would otherwise discover it
+    // lazily on the first page request, re-optimize, and trigger a full reload.
+    // That reload makes already-optimized deps (including the dev toolbar's
+    // runtime) return 504 "Outdated Optimize Dep", which breaks the Astro Dev
+    // Toolbar that the audit relies on. Listing it here optimizes it up front
+    // so the first navigation is stable.
+    optimizeDeps: {
+      include: ['@plausible-analytics/tracker'],
+    },
     server: {
       watch: {
         // Avoid inotify instance limits in dev containers and mounted volumes.