diff --git a/package.json b/package.json
index af476de757..49e6affe2a 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,6 @@
     "grant": "4.7.0",
     "helmet": "^4.6.0",
     "ipaddr.js": "^2.0.1",
-    "isobject": "3.0.1",
     "jsonwebtoken": "8.5.1",
     "lodash.merge": "^4.6.2",
     "mime-types": "2.1.25",
diff --git a/src/server/Uploader.js b/src/server/Uploader.js
index 8ddc8fc4d4..7bba45d1f0 100644
--- a/src/server/Uploader.js
+++ b/src/server/Uploader.js
@@ -1,7 +1,6 @@
 // eslint-disable-next-line max-classes-per-file
 const tus = require('tus-js-client')
 const { randomUUID } = require('node:crypto')
-const isObject = require('isobject')
 const validator = require('validator')
 const request = require('request')
 const { pipeline: pipelineCb } = require('node:stream')
@@ -78,17 +77,17 @@ function validateOptions (options) {
   }
 
   // validate fieldname
-  if (options.fieldname && typeof options.fieldname !== 'string') {
+  if (options.fieldname != null && typeof options.fieldname !== 'string') {
     throw new ValidationError('fieldname must be a string')
   }
 
   // validate metadata
-  if (options.metadata != null) {
-    if (!isObject(options.metadata)) throw new ValidationError('metadata must be an object')
+  if (options.metadata != null && typeof options.metadata !== 'object') {
+    throw new ValidationError('metadata must be an object')
   }
 
   // validate headers
-  if (options.headers && !isObject(options.headers)) {
+  if (options.headers != null && typeof options.headers !== 'object') {
     throw new ValidationError('headers must be an object')
   }
 
diff --git a/src/server/header-blacklist.js b/src/server/header-blacklist.js
index 08e0e4b817..5e188bad40 100644
--- a/src/server/header-blacklist.js
+++ b/src/server/header-blacklist.js
@@ -1,4 +1,3 @@
-const isObject = require('isobject')
 const logger = require('./logger')
 
 /**
@@ -50,7 +49,7 @@ const isForbiddenHeader = (header) => {
 }
 
 module.exports = (headers) => {
-  if (!isObject(headers)) {
+  if (headers == null || typeof headers !== 'object' || Array.isArray(headers)) {
     return {}
   }