diff --git a/content/base/src/nsXMLHttpRequest.cpp b/content/base/src/nsXMLHttpRequest.cpp
index 06e4133852dd..bb2add7c710e 100644
--- a/content/base/src/nsXMLHttpRequest.cpp
+++ b/content/base/src/nsXMLHttpRequest.cpp
@@ -1899,7 +1899,11 @@ nsXMLHttpRequest::OnStartRequest(nsIRequest *request, nsISupports *ctxt)
       mProgressTimerIsActive = false;
       mProgressNotifier->Cancel();
     }
-    MaybeDispatchProgressEvents(true);
+    if (mUploadTransferred < mUploadTotal) {
+      mUploadTransferred = mUploadTotal;
+      mProgressSinceLastProgressEvent = true;
+      MaybeDispatchProgressEvents(true);
+    }
     mUploadComplete = true;
     DispatchProgressEvent(mUpload, NS_LITERAL_STRING(LOAD_STR),
                           true, mUploadTotal, mUploadTotal);
@@ -3410,9 +3414,6 @@ nsXMLHttpRequest::MaybeDispatchProgressEvents(bool aFinalProgress)
   // We're uploading if our state is XML_HTTP_REQUEST_OPENED or
   // XML_HTTP_REQUEST_SENT
   if ((XML_HTTP_REQUEST_OPENED | XML_HTTP_REQUEST_SENT) & mState) {
-    if (aFinalProgress) {
-      mUploadTotal = mUploadTransferred;
-    }
     if (mUpload && !mUploadComplete) {
       DispatchProgressEvent(mUpload, NS_LITERAL_STRING(PROGRESS_STR),
                             mUploadLengthComputable, mUploadTransferred,
diff --git a/content/base/test/test_bug435425.html b/content/base/test/test_bug435425.html
index eb778799c434..511e816255ff 100644
--- a/content/base/test/test_bug435425.html
+++ b/content/base/test/test_bug435425.html
@@ -23,6 +23,7 @@ var xhr = null;
 var upload = null;
 var currentEvents = null;
 var expectedResponseText = null;
+var uploadTotal = 0;
 
 function logEvent(evt) {
   var i = 0;
@@ -32,6 +33,13 @@ function logEvent(evt) {
           !(evt.target instanceof currentEvents[i].target))) {
     ++i;
   }
+  if (evt.target instanceof XMLHttpRequestUpload) {
+    if (evt.type == "loadstart") {
+      uploadTotal = evt.total
+    } else {
+      is(evt.total, uploadTotal, "event(" + evt.type +  ").total should not change during upload.");
+    }
+  }
   ok(i != currentEvents.length, "Extra or wrong event?");
   is(evt.type, currentEvents[i].type, "Wrong event!")
   ok(evt.target instanceof currentEvents[i].target,