diff --git a/lib/web/imageRouter/index.js b/lib/web/imageRouter/index.js
index 7e555f9cd..ca0ebd00e 100644
--- a/lib/web/imageRouter/index.js
+++ b/lib/web/imageRouter/index.js
@@ -4,6 +4,7 @@ const Router = require('express').Router
 const formidable = require('formidable')
 const path = require('path')
 const fs = require('fs')
+const { v4: uuidv4 } = require('uuid');
 const os = require('os')
 const rimraf = require('rimraf')
 const isSvg = require('is-svg')
@@ -70,7 +71,13 @@ imageRouter.post('/uploadimage', function (req, res) {
   const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'hedgedoc-'))
   const form = formidable({
     keepExtensions: true,
-    uploadDir: tmpDir
+    uploadDir: tmpDir,
+    filename: function(filename, ext) {
+        if (typeof ext !== "string") {
+            ext = ".invalid"
+        }
+        return uuidv4() + ext
+    }
   })
 
   form.parse(req, async function (err, fields, files) {