diff --git a/packages/puppeteer-extra/package.json b/packages/puppeteer-extra/package.json
index 0bf15f90..4873e4c3 100644
--- a/packages/puppeteer-extra/package.json
+++ b/packages/puppeteer-extra/package.json
@@ -66,7 +66,8 @@
     "@types/debug": "^4.1.0",
     "@types/puppeteer": "*",
     "debug": "^4.1.1",
-    "deepmerge": "^4.2.2"
+    "deepmerge": "^4.2.2",
+    "is-plain-object": "^5.0.0"
   },
   "gitHead": "babb041828cab50c525e0b9aab02d58f73416ef3"
 }
diff --git a/packages/puppeteer-extra/src/index.ts b/packages/puppeteer-extra/src/index.ts
index 4638ba6d..0d2d6389 100644
--- a/packages/puppeteer-extra/src/index.ts
+++ b/packages/puppeteer-extra/src/index.ts
@@ -4,6 +4,7 @@ import Debug from 'debug'
 const debug = Debug('puppeteer-extra')
 
 import merge from 'deepmerge'
+import {isPlainObject} from 'is-plain-object'
 
 /**
  * Original Puppeteer API
@@ -153,7 +154,8 @@ export class PuppeteerExtra implements VanillaPuppeteer {
   async launch(options?: Puppeteer.LaunchOptions): Promise<Puppeteer.Browser> {
     // Ensure there are certain properties (e.g. the `options.args` array)
     const defaultLaunchOptions = { args: [] }
-    options = merge(defaultLaunchOptions, options || {} as any)
+    options = merge(defaultLaunchOptions, options || {} as any, { "isMergeableObject": isPlainObject })
+
     this.resolvePluginDependencies()
     this.orderPlugins()