diff --git a/src/platform.ts b/src/platform.ts
index 34810889..ee205da6 100644
--- a/src/platform.ts
+++ b/src/platform.ts
@@ -137,6 +137,9 @@ export class App {
     await this.removeDefaultApp();
     if (this.opts.prebuiltAsar) {
       await this.copyPrebuiltAsar();
+      this.asarIntegrity = {
+        [this.appRelativePath(this.appAsarPath)]: this.getAsarIntegrity(this.appAsarPath),
+      };
     } else {
       await this.buildApp();
     }
@@ -243,18 +246,22 @@ export class App {
     await promisifyHooks(this.opts.beforeAsar, this.hookArgsWithOriginalResourcesAppDir);
 
     await asar.createPackageWithOptions(this.originalResourcesAppDir, this.appAsarPath, this.asarOptions);
-    const { headerString } = asar.getRawHeader(this.appAsarPath);
     this.asarIntegrity = {
-      [this.appRelativePath(this.appAsarPath)]: {
-        algorithm: 'SHA256',
-        hash: crypto.createHash('SHA256').update(headerString).digest('hex'),
-      },
+      [this.appRelativePath(this.appAsarPath)]: this.getAsarIntegrity(this.appAsarPath),
     };
     await fs.remove(this.originalResourcesAppDir);
 
     await promisifyHooks(this.opts.afterAsar, this.hookArgsWithOriginalResourcesAppDir);
   }
 
+  getAsarIntegrity(path: string): Pick<FileRecord['integrity'], 'algorithm' | 'hash'> {
+    const { headerString } = asar.getRawHeader(path);
+    return {
+      algorithm: 'SHA256',
+      hash: crypto.createHash('SHA256').update(headerString).digest('hex'),
+    };
+  }
+
   async copyExtraResources() {
     if (!this.opts.extraResource) {
       return Promise.resolve();
diff --git a/test/darwin.js b/test/darwin.js
index b8a0dc1e..cc4aba72 100644
--- a/test/darwin.js
+++ b/test/darwin.js
@@ -498,4 +498,22 @@ if (!(process.env.CI && process.platform === 'win32')) {
       }
     })
   }))
+
+  test.serial('prebuilt asar integrity hashes are automatically inserted', darwinTest(async (t, baseOpts) => {
+    const opts = {
+      ...baseOpts,
+      dir: util.fixtureSubdir('asar-prebuilt')
+    }
+    opts.prebuiltAsar = path.join(opts.dir, 'app.asar')
+    const finalPath = (await packager(opts))[0]
+    const plistObj = await parseInfoPlist(t, opts, finalPath)
+    t.is(typeof plistObj.ElectronAsarIntegrity, 'object')
+    // Note: If you update test/fixtures/asar-prebuilt/app.asar, ths hash should also be updated.
+    t.deepEqual(plistObj.ElectronAsarIntegrity, {
+      'Resources/app.asar': {
+        algorithm: 'SHA256',
+        hash: '5efe069acf1f8d2622f2da149fcedcd5e17f9e7f4bc6f7ffe89255ee96647d4f'
+      }
+    })
+  }))
 }