diff --git a/package-lock.json b/package-lock.json
index 5ef898e..2b46491 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1857,7 +1857,7 @@
     },
     "node_modules/@quartz-community/utils": {
       "version": "0.1.0",
-      "resolved": "git+ssh://git@github.com/quartz-community/utils.git#83f824b0ad495ae24b7f3524dd2049da76d24c2c",
+      "resolved": "git+ssh://git@github.com/quartz-community/utils.git#7a43501ac1c728e8a7bfa75db35e8791bfa1f41c",
       "dev": true,
       "license": "MIT",
       "dependencies": {
diff --git a/quartz/components/pages/404.tsx b/quartz/components/pages/404.tsx
index dafabad..622a18d 100644
--- a/quartz/components/pages/404.tsx
+++ b/quartz/components/pages/404.tsx
@@ -16,13 +16,13 @@ const NotFound: QuartzComponent = ({ cfg }: QuartzComponentProps) => {
           __html: `
           if (typeof fetchData !== "undefined") {
             fetchData.then(function(index) {
-              var base = document.querySelector("base");
-              var basePath = (base && base.getAttribute("href")) || "/";
+              var basePath = document.body.dataset.basepath || "";
               if (basePath.length > 1 && basePath.endsWith("/")) {
                 basePath = basePath.slice(0, -1);
               }
               var pathname = window.location.pathname;
-              if (basePath.length > 1 && pathname.startsWith(basePath)) {
+              var hasBasePrefix = basePath.length > 1 && pathname.startsWith(basePath);
+              if (hasBasePrefix) {
                 pathname = pathname.slice(basePath.length);
               }
               if (pathname.startsWith("/")) {
@@ -31,17 +31,16 @@ const NotFound: QuartzComponent = ({ cfg }: QuartzComponentProps) => {
               if (pathname.endsWith("/")) {
                 pathname = pathname.slice(0, -1);
               }
-              // Strip .html extension if present
               if (pathname.endsWith(".html")) {
                 pathname = pathname.slice(0, -5);
               }
-              // Convert trailing /index to folder slug
               if (pathname.endsWith("/index")) {
                 pathname = pathname.slice(0, -6);
               }
               var lowered = pathname.toLowerCase();
               if (lowered !== pathname && index[lowered] != null) {
-                var target = basePath + (basePath.endsWith("/") ? "" : "/") + lowered;
+                var prefix = hasBasePrefix ? basePath : "";
+                var target = prefix + (prefix.endsWith("/") ? "" : "/") + lowered;
                 window.location.replace(target);
               }
             });
diff --git a/quartz/plugins/pageTypes/dispatcher.ts b/quartz/plugins/pageTypes/dispatcher.ts
index aa853af..543cb07 100644
--- a/quartz/plugins/pageTypes/dispatcher.ts
+++ b/quartz/plugins/pageTypes/dispatcher.ts
@@ -78,10 +78,15 @@ async function emitPage(
 ) {
   const cfg = ctx.cfg.configuration
   // For the 404 page, use an absolute base path so assets resolve correctly
-  // when the hosting provider serves 404.html from any URL depth
+  // when the hosting provider serves 404.html from any URL depth.
+  // During local dev (--serve), the dev server strips baseDir itself and
+  // serves files from root, so the 404 page must use "/" to avoid requesting
+  // assets under a path prefix that the dev server doesn't serve.
   const baseDir =
     slug === "404"
-      ? (new URL(`https://${cfg.baseUrl ?? "example.com"}`).pathname as FullSlug)
+      ? ((ctx.argv.serve
+          ? "/"
+          : new URL(`https://${cfg.baseUrl ?? "example.com"}`).pathname) as FullSlug)
       : pathToRoot(slug)
   const externalResources = pageResources(baseDir, resources)
   const componentData: QuartzComponentProps = {
diff --git a/quartz/util/path.test.ts b/quartz/util/path.test.ts
index b6fb9fb..c143414 100644
--- a/quartz/util/path.test.ts
+++ b/quartz/util/path.test.ts
@@ -170,6 +170,15 @@ describe("transforms", () => {
         ["content/with spaces", "./content/with-spaces"],
         ["content/with spaces/index", "./content/with-spaces/"],
         ["content/with spaces#and Anchor!", "./content/with-spaces#and-anchor"],
+        // Folder note convention: same-name parent triggers /index rewrite → folder path
+        ["characters/characters", "./characters/"],
+        ["My Folder/My Folder", "./my-folder/"],
+        ["a/b/c/d/d", "./a/b/c/d/"],
+        ["My Folder/My Folder#heading", "./my-folder/#heading"],
+        // Non-matching last segments: no folder rewrite
+        ["characters/alice", "./characters/alice"],
+        // Percent-encoded spaces
+        ["My%20Folder/My%20Note", "./my-folder/my-note"],
       ],
       path.transformInternalLink,
       (_x: string): _x is string => true,