diff --git a/main.js b/main.js
index 19e6172a..ee95726c 100644
--- a/main.js
+++ b/main.js
@@ -2746,8 +2746,17 @@ async function serveBns(request) {
         ? up.contentType : guessType(reqPath === "/" ? "index.html" : reqPath);
       let body = up.buffer;
       if (ct.includes("text/html")) {
-        // Strip the gateway's path-form <base href="/bns/<name>/"> so assets
-        // resolve against the bns:// origin, not back through the relay.
+        // Translate the gateway's path-form <base href="/bns/<name>/…"> to
+        // a bns://<name>/… base so assets resolve against the bns:// origin.
+        // Previously we stripped the tag entirely, which worked when the
+        // gateway's base matched the request path, but broke on any SPA
+        // fallback: hitting bns://pithos.sia/HouseMusic/house-music served
+        // the site's root index with <base href="/bns/pithos.sia/">, and
+        // stripping that let the browser use bns://pithos.sia/HouseMusic/
+        // as the implicit base — so `assets/logo.svg` on the root page
+        // resolved one folder too deep and 404d. Keeping the gateway's
+        // base (translated to bns://) honours the gateway's SPA fix for
+        // Theseus too.
         // Also strip the gateway's relay chrome (banner + chip + their boot
         // script) in case an older gateway, a misconfigured deployment, or
         // a cached edge missed the x-bns-policy signal and injected it
@@ -2757,7 +2766,7 @@ async function serveBns(request) {
         // for exactly this kind of surgical removal.
         body = Buffer.from(
           body.toString("utf8")
-            .replace(/<base\s+href="\/bns\/[^"]*">/i, "")
+            .replace(/<base\s+href="\/bns\/([^"]*)">/i, (_, tail) => `<base href="bns://${tail}">`)
             .replace(/<!--nav-relay-banner-start-->[\s\S]*?<!--nav-relay-banner-end-->/gi, "")
             .replace(/<!--nav-relay-chip-start-->[\s\S]*?<!--nav-relay-chip-end-->/gi, "")
             .replace(/<!--nav-relay-script-start-->[\s\S]*?<!--nav-relay-script-end-->/gi, ""),