diff --git a/src/vs/workbench/test/browser/api/extHostWorkspace.test.ts b/src/vs/workbench/test/browser/api/extHostWorkspace.test.ts
index b36ec55951c..a3eacd6e298 100644
--- a/src/vs/workbench/test/browser/api/extHostWorkspace.test.ts
+++ b/src/vs/workbench/test/browser/api/extHostWorkspace.test.ts
@@ -605,7 +605,7 @@ suite('ExtHostWorkspace', function () {
 		});
 	});
 
-	test('findFiles - RelativePattern include', () => {
+	function testFindFilesInclude(pattern: RelativePattern) {
 		const root = '/project/foo';
 		const rpcProtocol = new TestRPCProtocol();
 
@@ -614,16 +614,24 @@ suite('ExtHostWorkspace', function () {
 			$startFileSearch(includePattern: string, _includeFolder: UriComponents | null, excludePatternOrDisregardExcludes: string | false, maxResults: number, token: CancellationToken): Promise<URI[] | null> {
 				mainThreadCalled = true;
 				assert.equal(includePattern, 'glob/**');
-				assert.deepEqual(_includeFolder, URI.file('/other/folder').toJSON());
+				assert.deepEqual(_includeFolder ? URI.from(_includeFolder).toJSON() : null, URI.file('/other/folder').toJSON());
 				assert.equal(excludePatternOrDisregardExcludes, null);
 				return Promise.resolve(null);
 			}
 		});
 
 		const ws = createExtHostWorkspace(rpcProtocol, { id: 'foo', folders: [aWorkspaceFolderData(URI.file(root), 0)], name: 'Test' }, new NullLogService());
-		return ws.findFiles(new RelativePattern('/other/folder', 'glob/**'), undefined, 10, new ExtensionIdentifier('test')).then(() => {
+		return ws.findFiles(pattern, undefined, 10, new ExtensionIdentifier('test')).then(() => {
 			assert(mainThreadCalled, 'mainThreadCalled');
 		});
+	}
+
+	test('findFiles - RelativePattern include (string)', () => {
+		return testFindFilesInclude(new RelativePattern('/other/folder', 'glob/**'));
+	});
+
+	test('findFiles - RelativePattern include (URI)', () => {
+		return testFindFilesInclude(new RelativePattern(URI.file('/other/folder'), 'glob/**'));
 	});
 
 	test('findFiles - no excludes', () => {