diff --git a/src/vs/workbench/browser/actions/workspaceCommands.ts b/src/vs/workbench/browser/actions/workspaceCommands.ts
index e6abcd0b5aa8c50cd56ee31b01d71bcebed209ec..2ef4aa69ab4135526b65c937d275ab72b8175ca3 100644
--- a/src/vs/workbench/browser/actions/workspaceCommands.ts
+++ b/src/vs/workbench/browser/actions/workspaceCommands.ts
@@ -144,13 +144,13 @@ CommandsRegistry.registerCommand({
 CommandsRegistry.registerCommand({
 	id: ADD_ROOT_FOLDER_COMMAND_ID,
 	handler: (accessor) => {
+		const viewletService = accessor.get(IViewletService);
+		const workspaceEditingService = accessor.get(IWorkspaceEditingService);
 		return pickFolders(mnemonicButtonLabel(nls.localize({ key: 'add', comment: ['&& denotes a mnemonic'] }, "&&Add")), nls.localize('addFolderToWorkspaceTitle', "Add Folder to Workspace"),
 			accessor.get(IWindowService), accessor.get(IWorkspaceContextService), accessor.get(IHistoryService)).then(folders => {
 				if (!folders || !folders.length) {
 					return null;
 				}
-				const viewletService = accessor.get(IViewletService);
-				const workspaceEditingService = accessor.get(IWorkspaceEditingService);
 
 				// Add and show Files Explorer viewlet
 				return workspaceEditingService.addFolders(folders.map(folder => ({ uri: URI.file(folder) }))).then(() => viewletService.openViewlet(viewletService.getDefaultViewletId(), true));
diff --git a/src/vs/workbench/parts/preferences/browser/preferencesActions.ts b/src/vs/workbench/parts/preferences/browser/preferencesActions.ts
index 66f05a694d650045ea05a8da1a6d75768b730308..0399b803ed0966f9ef9d4089ffba6f823abd826a 100644
--- a/src/vs/workbench/parts/preferences/browser/preferencesActions.ts
+++ b/src/vs/workbench/parts/preferences/browser/preferencesActions.ts
@@ -150,7 +150,7 @@ export class OpenFolderSettingsAction extends Action {
 		return this.commandService.executeCommand<IWorkspaceFolder>(PICK_WORKSPACE_FOLDER_COMMAND_ID)
 			.then(workspaceFolder => {
 				if (workspaceFolder) {
-					return this.commandService.executeCommand(OPEN_FOLDER_SETTINGS_COMMAND, workspaceFolder);
+					return this.commandService.executeCommand(OPEN_FOLDER_SETTINGS_COMMAND, workspaceFolder.uri);
 				}
 				return null;
 			});
diff --git a/src/vs/workbench/parts/preferences/electron-browser/preferences.contribution.ts b/src/vs/workbench/parts/preferences/electron-browser/preferences.contribution.ts
index c448009c688ba3a38dc7cac117221500bcb1c359..7ffe68c35dce60c08581fcae62c1faa70cd35be7 100644
--- a/src/vs/workbench/parts/preferences/electron-browser/preferences.contribution.ts
+++ b/src/vs/workbench/parts/preferences/electron-browser/preferences.contribution.ts
@@ -263,7 +263,7 @@ KeybindingsRegistry.registerCommandAndKeybindingRule({
 
 Registry.as<IWorkbenchContributionsRegistry>(WorkbenchExtensions.Workbench).registerWorkbenchContribution(PreferencesContribution, LifecyclePhase.Starting);
 
-CommandsRegistry.registerCommand(OPEN_FOLDER_SETTINGS_COMMAND, function (accessor: ServicesAccessor, args?: IWorkspaceFolder) {
+CommandsRegistry.registerCommand(OPEN_FOLDER_SETTINGS_COMMAND, function (accessor: ServicesAccessor, resource: URI) {
 	const preferencesService = accessor.get(IPreferencesService);
-	return preferencesService.openFolderSettings(args.uri);
-});
\ No newline at end of file
+	return preferencesService.openFolderSettings(resource);
+});