diff --git a/lib/upload.js b/lib/upload.js
index e2577758..4365388f 100644
--- a/lib/upload.js
+++ b/lib/upload.js
@@ -73,6 +73,9 @@ class Upload {
 
     // The offset of the remote upload before the latest attempt was started.
     this._offsetBeforeRetry = 0;
+
+    // The remote upload resource is deferred
+    this._deferred = false;
   }
 
   static terminate(url, options, cb) {
@@ -401,6 +404,7 @@ class Upload {
     this._setupXHR(xhr);
     if (this.options.uploadLengthDeferred) {
       xhr.setRequestHeader("Upload-Defer-Length", 1);
+      this._deferred = true;
     } else {
       xhr.setRequestHeader("Upload-Length", this._size);
     }
@@ -470,8 +474,13 @@ class Upload {
         return;
       }
 
+      let deferLength = parseInt(xhr.getResponseHeader("Upload-Defer-Length"), 10);
+      if (deferLength === 1) {
+        this._deferred = true;
+      }
+
       let length = parseInt(xhr.getResponseHeader("Upload-Length"), 10);
-      if (isNaN(length) && !this.options.uploadLengthDeferred) {
+      if (isNaN(length) && !this._deferred) {
         this._emitXhrError(xhr, new Error("tus: invalid or missing length value"));
         return;
       }
@@ -581,10 +590,11 @@ class Upload {
         return;
       }
 
-      if (this.options.uploadLengthDeferred) {
-        if (complete) {
+      if (this.options.uploadLengthDeferred || this._deferred) {
+        if (!this.options.uploadLengthDeferred || complete) {
           this._size = this._offset + (value && value.size ? value.size : 0);
           xhr.setRequestHeader("Upload-Length", this._size);
+          this._deferred = false;
         }
       }