diff --git a/src/vs/workbench/api/node/apiCommands.ts b/src/vs/workbench/api/node/apiCommands.ts
index d45fa9d6195..0e228988d60 100644
--- a/src/vs/workbench/api/node/apiCommands.ts
+++ b/src/vs/workbench/api/node/apiCommands.ts
@@ -55,7 +55,7 @@ export class OpenFolderAPICommand {
 			uri = correctedUri;
 		}
 
-		return executor.executeCommand('_files.windowOpen', [uri], forceNewWindow);
+		return executor.executeCommand('_files.windowOpen', { folderURIs: [uri], forceNewWindow });
 	}
 }
 CommandsRegistry.registerCommand(OpenFolderAPICommand.ID, adjustHandler(OpenFolderAPICommand.execute));
diff --git a/src/vs/workbench/parts/files/electron-browser/fileCommands.ts b/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
index b45e20aed65..e6f4b1e4b9a 100644
--- a/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
+++ b/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
@@ -76,9 +76,18 @@ export const ResourceSelectedForCompareContext = new RawContextKey<boolean>('res
 export const REMOVE_ROOT_FOLDER_COMMAND_ID = 'removeRootFolder';
 export const REMOVE_ROOT_FOLDER_LABEL = nls.localize('removeFolderFromWorkspace', "Remove Folder from Workspace");
 
-export const openWindowCommand = (accessor: ServicesAccessor, paths: Array<string | URI>, forceNewWindow: boolean) => {
+export const openWindowCommand = (accessor: ServicesAccessor, input: Array<string | URI> | { fileURIs: URI[], folderURIs: URI[], forceNewWindow: boolean }, forceNewWindow: boolean) => {
 	const windowService = accessor.get(IWindowService);
-	windowService.openWindow(paths.map(p => typeof p === 'string' ? URI.file(p) : p), { forceNewWindow });
+	if (Array.isArray(input)) {
+		windowService.openWindow(input.map(p => typeof p === 'string' ? URI.file(p) : p), { forceNewWindow });
+	} else if (input) {
+		if (Array.isArray(input.folderURIs) && input.folderURIs.length) {
+			windowService.openWindow(input.folderURIs, { forceNewWindow: input.forceNewWindow });
+		}
+		if (Array.isArray(input.fileURIs) && input.fileURIs.length) {
+			windowService.openWindow(input.fileURIs, { forceNewWindow: input.forceNewWindow, forceOpenWorkspaceAsFile: true });
+		}
+	}
 };
 
 function save(