diff --git a/package.json b/package.json
index 4a0f38b8..292be067 100644
--- a/package.json
+++ b/package.json
@@ -121,7 +121,6 @@
     "get-port": "^7.0.0",
     "giget": "^1.1.3",
     "hookable": "^5.5.3",
-    "immer": "^10.0.3",
     "is-wsl": "^3.0.0",
     "jiti": "^1.21.0",
     "json5": "^2.2.3",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index c9b482f0..d3b1011d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -62,9 +62,6 @@ importers:
       hookable:
         specifier: ^5.5.3
         version: 5.5.3
-      immer:
-        specifier: ^10.0.3
-        version: 10.0.3
       is-wsl:
         specifier: ^3.0.0
         version: 3.1.0
@@ -2930,10 +2927,6 @@ packages:
     resolution: {integrity: sha512-XXOFtyqDjNDAQxVfYxuF7g9Il/IbWmmlQg2MYKOH8ExIT1qg6xc4zyS3HaEEATgs1btfzxq15ciUiY7gjSXRGQ==}
     dev: false
 
-  /immer@10.0.3:
-    resolution: {integrity: sha512-pwupu3eWfouuaowscykeckFmVTpqbzW+rXFCX8rQLkZzM9ftBmU/++Ra+o+L27mz03zJTlyV4UUr+fdKNffo4A==}
-    dev: false
-
   /immutable@4.3.4:
     resolution: {integrity: sha512-fsXeu4J4i6WNWSikpI88v/PcVflZz+6kMhUfIwc5SY+poQRPnaf5V7qds6SUyUN3cVxEzuCab7QIoLOQ+DQ1wA==}
 
diff --git a/src/core/utils/manifest.ts b/src/core/utils/manifest.ts
index 3eab77d4..2a13e757 100644
--- a/src/core/utils/manifest.ts
+++ b/src/core/utils/manifest.ts
@@ -21,7 +21,6 @@ import {
 import { getPackageJson } from './package';
 import { normalizePath } from './paths';
 import { writeFileIfDifferent } from './fs';
-import { produce } from 'immer';
 import defu from 'defu';
 import { wxt } from '../wxt';
 
@@ -113,21 +112,22 @@ export async function generateManifest(
   if (wxt.config.command === 'serve') addDevModeCsp(manifest);
   if (wxt.config.command === 'serve') addDevModePermissions(manifest);
 
-  const finalManifest = produce(manifest, wxt.config.transformManifest);
-  await wxt.hooks.callHook('build:manifestGenerated', wxt, finalManifest);
+  // TODO: Remove in v1
+  wxt.config.transformManifest(manifest);
+  await wxt.hooks.callHook('build:manifestGenerated', wxt, manifest);
 
-  if (finalManifest.name == null)
+  if (manifest.name == null)
     throw Error(
       "Manifest 'name' is missing. Either:\n1. Set the name in your <rootDir>/package.json\n2. Set a name via the manifest option in your wxt.config.ts",
     );
-  if (finalManifest.version == null) {
+  if (manifest.version == null) {
     throw Error(
       "Manifest 'version' is missing. Either:\n1. Add a version in your <rootDir>/package.json\n2. Pass the version via the manifest option in your wxt.config.ts",
     );
   }
 
   return {
-    manifest: finalManifest,
+    manifest,
     warnings,
   };
 }