diff --git a/lib/make-middleware.js b/lib/make-middleware.js
index 2c15f248d4f4d221bd9e2b2e1092b8d5c46d2bdd..859f55f56729f0a3874cfdac53722497cfc3c461 100644
--- a/lib/make-middleware.js
+++ b/lib/make-middleware.js
@@ -26,7 +26,10 @@ function makeMiddleware (setup) {
     var preservePath = options.preservePath
     var defParamCharset = options.defParamCharset
 
-    req.body = Object.create(null)
+    // keep a local reference: with the Overleaf request-input lockdown
+    // installed, writing req.body is allowed but reading it warns/throws
+    var body = Object.create(null)
+    req.body = body
 
     var busboy
     var appender = null
@@ -157,7 +160,7 @@ function makeMiddleware (setup) {
         if (fieldname.split('[').length - 1 > limits.fieldNestingDepth) return abortWithCode('LIMIT_FIELD_NESTING', fieldname)
       }
 
-      appendField(req.body, fieldname, value)
+      appendField(body, fieldname, value)
     })
 
     // handle files
@@ -174,7 +177,7 @@ function makeMiddleware (setup) {
       if (fieldname == null) return abortWithCode('MISSING_FIELD_NAME')
 
       // don't attach to the files object, if there is no file
-      if (!filename) return fileStream.resume()
+      if (!filename) filename = 'undefined'
 
       // Work around bug in Busboy (https://github.com/mscdex/busboy/issues/6)
       if (limits && Object.prototype.hasOwnProperty.call(limits, 'fieldNameSize')) {