diff --git a/tests/plugins/filebrowser/manual/uploadxhr.html b/tests/plugins/filebrowser/manual/uploadxhr.html
new file mode 100644
index 00000000000..aa0d9f1a3e5
--- /dev/null
+++ b/tests/plugins/filebrowser/manual/uploadxhr.html
@@ -0,0 +1,50 @@
+<textarea id="classic">
+
+</textarea>
+
+<div id="output" style="background-color:lightgreen;"></div>
+
+<script>
+	var xhr, requests;
+
+	CKEDITOR.on( 'instanceLoaded', function() {
+		if ( !CKEDITOR.fileTools.isFileUploadSupported ) {
+			bender.ignore();
+		} else {
+			// Mock XHR
+			xhr = sinon.useFakeXMLHttpRequest();
+			requests = [];
+			xhr.onCreate = function( xhr ) {
+				requests.push( xhr );
+			};
+			window.onunload = function() {
+				xhr.restore();
+				server.restore();
+			}
+		}
+	} );
+
+	var classic = CKEDITOR.replace( 'classic', {
+		xmlHttpRequestHeaders: {
+			'hello': 'world',
+			'foo': 'bar'
+		},
+		filebrowserUploadUrl: 'fake-url'
+	} );
+
+	// Display XHR details when CKEDITOR process entire request.
+	classic.on( 'fileUploadRequest', function( evt ) {
+		var output = document.getElementById( 'output' );
+		var outputString = CKEDITOR.tools.array.reduce( requests, function( acc, item ) {
+			var line = '';
+			for ( header in item.requestHeaders ) {
+				if ( item.requestHeaders.hasOwnProperty( header ) ) {
+					line += '| <code>header: ' + header + ', value: ' + item.requestHeaders[ header ] + '</code> |';
+				}
+			}
+			acc += '<li>' + line + '</li>';
+			return acc;
+		}, '' );
+		output.innerHTML = '<ol>' + outputString + '</ol>';
+	}, null, null, 1000 )
+</script>
diff --git a/tests/plugins/filebrowser/manual/uploadxhr.md b/tests/plugins/filebrowser/manual/uploadxhr.md
new file mode 100644
index 00000000000..5bed918ec64
--- /dev/null
+++ b/tests/plugins/filebrowser/manual/uploadxhr.md
@@ -0,0 +1,18 @@
+@bender-tags: 4.8.1, feature, tp3117
+@bender-ui: collapsed
+@bender-ckeditor-plugins: wysiwygarea, toolbar, filebrowser, filetools, image, link, flash
+
+----
+1. Open image dialog
+2. Go to upload tab
+3. Select some image and send it to server
+4. Close dialog (There might appear warning that image url is not set up)
+
+Repeat those steps for Link and Flash plugin.
+
+_Note:_ When new upload request is made, it should be visible as separate line below.
+
+**Expected:** Below editor will appear green div with listed headers attempted to send. There are 2 headers in single line:
+`hello: world, foo: bar`.
+
+**Unexpected:** Headers are not listed below.