diff --git a/src/options.ts b/src/options.ts
index f6a777bff9..1b6b10fa92 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -3,7 +3,11 @@ import { loadConfig, watchConfig, WatchConfigOptions } from "c12";
 import { klona } from "klona/full";
 import { camelCase } from "scule";
 import { defu } from "defu";
-import { resolveModuleExportNames, resolvePath as resolveModule } from "mlly";
+import {
+  resolveModuleExportNames,
+  resolvePath as resolveModule,
+  parseNodeModulePath,
+} from "mlly";
 import escapeRE from "escape-string-regexp";
 import { withLeadingSlash, withoutTrailingSlash, withTrailingSlash } from "ufo";
 import { isTest, isDebug } from "std-env";
@@ -314,9 +318,16 @@ export async function loadOptions(
     serverAsset.dir = resolve(options.srcDir, serverAsset.dir);
   }
 
-  for (const pkg of ["defu", "h3", "radix3"]) {
-    if (!options.alias[pkg]) {
-      options.alias[pkg] = await resolveModule(pkg, { url: import.meta.url });
+  // Dedup built-in dependencies
+  for (const pkg of ["defu", "h3", "radix3", "unstorage"]) {
+    const entryPath = await resolveModule(pkg, { url: import.meta.url });
+    const { dir, name } = parseNodeModulePath(entryPath);
+    if (!dir || !name) {
+      continue;
+    }
+    if (!options.alias[pkg + "/"]) {
+      const pkgDir = join(dir, name);
+      options.alias[pkg + "/"] = pkgDir;
     }
   }