diff --git a/chrome/content/scaffold/scaffold.js b/chrome/content/scaffold/scaffold.js
index 255735a8de..37663280d1 100644
--- a/chrome/content/scaffold/scaffold.js
+++ b/chrome/content/scaffold/scaffold.js
@@ -24,6 +24,7 @@
 */
 
 Components.utils.import("resource://gre/modules/Services.jsm");
+import FilePicker from 'zotero/filePicker';
 
 var Zotero = Components.classes["@zotero.org/Zotero;1"]
 				// Currently uses only nsISupports
@@ -70,7 +71,7 @@ var Scaffold = new function() {
 		'textbox-hidden-prefs':'hiddenPrefs'
 	};
 
-	this.onLoad = function (e) {
+	this.onLoad = async function (e) {
 		if(e.target !== document) return;
 		_document = document;
 		
@@ -145,7 +146,7 @@ var Scaffold = new function() {
 		}
 		
 		if (!Scaffold_Translators.getDirectory()) {
-			if (!this.promptForTranslatorsDirectory()) {
+			if (!await this.promptForTranslatorsDirectory()) {
 				window.close();
 				return;
 			}
@@ -155,7 +156,7 @@ var Scaffold = new function() {
 		_translatorProvider = Scaffold_Translators.getProvider();
 	};
 	
-	this.promptForTranslatorsDirectory = function () {
+	this.promptForTranslatorsDirectory = async function () {
 		var ps = Services.prompt;
 		var buttonFlags = ps.BUTTON_POS_0 * ps.BUTTON_TITLE_IS_STRING
 			+ ps.BUTTON_POS_1 * ps.BUTTON_TITLE_IS_STRING
@@ -171,7 +172,7 @@ var Scaffold = new function() {
 		);
 		// Revert to home directory
 		if (index == 0) {
-			let dir = this.setTranslatorsDirectory();
+			let dir = await this.setTranslatorsDirectory();
 			if (dir) {
 				return true;
 			}
@@ -182,23 +183,22 @@ var Scaffold = new function() {
 		return false;
 	};
 	
-	this.setTranslatorsDirectory = function () {
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"].createInstance(nsIFilePicker);
+	this.setTranslatorsDirectory = async function () {
+		var fp = new FilePicker();
 		var oldPath = Zotero.Prefs.get('scaffold.translatorsDir');
 		if (oldPath) {
-			fp.displayDirectory = Zotero.File.pathToFile(oldPath);
+			fp.displayDirectory = oldPath;
 		}
 		fp.init(
 			window,
 			"Select Translators Directory",
-			nsIFilePicker.modeGetFolder
+			fp.modeGetFolder
 		);
-		fp.appendFilters(nsIFilePicker.filterAll);
-		if (fp.show() != nsIFilePicker.returnOK) {
+		fp.appendFilters(fp.filterAll);
+		if (await fp.show() != fp.returnOK) {
 			return false;
 		}
-		var path = OS.Path.normalize(fp.file.path);
+		var path = OS.Path.normalize(fp.file);
 		if (oldPath == path) {
 			return false;
 		}
diff --git a/chrome/content/zotero/fileInterface.js b/chrome/content/zotero/fileInterface.js
index bbd05957d6..2d6896dca7 100644
--- a/chrome/content/zotero/fileInterface.js
+++ b/chrome/content/zotero/fileInterface.js
@@ -24,6 +24,7 @@
 */
 
 Components.utils.import("resource://gre/modules/osfile.jsm")
+import FilePicker from 'zotero/filePicker';
 
 /****Zotero_File_Exporter****
  **
@@ -44,9 +45,9 @@ var Zotero_File_Exporter = function() {
  *
  * @return {Promise}
  **/
-Zotero_File_Exporter.prototype.save = Zotero.Promise.coroutine(function* () {
+Zotero_File_Exporter.prototype.save = async function () {
 	var translation = new Zotero.Translate.Export();
-	var translators = yield translation.getTranslators();
+	var translators = await translation.getTranslators();
 	
 	// present options dialog
 	var io = {translators:translators}
@@ -56,17 +57,15 @@ Zotero_File_Exporter.prototype.save = Zotero.Promise.coroutine(function* () {
 		return false;
 	}
 	
-	const nsIFilePicker = Components.interfaces.nsIFilePicker;
-	var fp = Components.classes["@mozilla.org/filepicker;1"]
-			.createInstance(nsIFilePicker);
-	fp.init(window, Zotero.getString("fileInterface.export"), nsIFilePicker.modeSave);
+	var fp = new FilePicker();
+	fp.init(window, Zotero.getString("fileInterface.export"), fp.modeSave);
 	
 	// set file name and extension
 	if(io.displayOptions.exportFileData) {
 		// if the result will be a folder, don't append any extension or use
 		// filters
 		fp.defaultString = this.name;
-		fp.appendFilters(Components.interfaces.nsIFilePicker.filterAll);
+		fp.appendFilters(fp.filterAll);
 	} else {
 		// if the result will be a file, append an extension and use filters
 		fp.defaultString = this.name+(io.selectedTranslator.target ? "."+io.selectedTranslator.target : "");
@@ -74,8 +73,8 @@ Zotero_File_Exporter.prototype.save = Zotero.Promise.coroutine(function* () {
 		fp.appendFilter(io.selectedTranslator.label, "*."+(io.selectedTranslator.target ? io.selectedTranslator.target : "*"));
 	}
 	
-	var rv = fp.show();
-	if (rv != nsIFilePicker.returnOK && rv != nsIFilePicker.returnReplace) {
+	var rv = await fp.show();
+	if (rv != fp.returnOK && rv != fp.returnReplace) {
 		return;
 	}
 	
@@ -89,7 +88,7 @@ Zotero_File_Exporter.prototype.save = Zotero.Promise.coroutine(function* () {
 		translation.setLibraryID(this.libraryID);
 	}
 	
-	translation.setLocation(fp.file);
+	translation.setLocation(Zotero.File.pathToFile(fp.file));
 	translation.setTranslator(io.selectedTranslator);
 	translation.setDisplayOptions(io.displayOptions);
 	translation.setHandler("itemDone", function () {
@@ -100,7 +99,7 @@ Zotero_File_Exporter.prototype.save = Zotero.Promise.coroutine(function* () {
 		Zotero.getString("fileInterface.itemsExported")
 	);
 	translation.translate()
-});
+};
 	
 /*
  * Closes the items exported indicator
@@ -593,7 +592,7 @@ var Zotero_File_Interface = new function() {
 	/**
 	 * Creates a bibliography from a collection or saved search
 	 */
-	this.bibliographyFromCollection = function () {
+	this.bibliographyFromCollection = async function () {
 		var items = ZoteroPane.getSortedItems();
 		
 		// Find collection name
@@ -609,17 +608,17 @@ var Zotero_File_Interface = new function() {
 			}
 		}
 		
-		_doBibliographyOptions(name, items);
+		await _doBibliographyOptions(name, items);
 	}
 	
 	/*
 	 * Creates a bibliography from a items
 	 */
-	function bibliographyFromItems() {
+	async function bibliographyFromItems() {
 		var items = ZoteroPane_Local.getSelectedItems();
 		if(!items || !items.length) throw("no items currently selected");
 		
-		_doBibliographyOptions(Zotero.getString("fileInterface.untitledBibliography"), items);
+		await _doBibliographyOptions(Zotero.getString("fileInterface.untitledBibliography"), items);
 	}
 	
 	
@@ -688,7 +687,7 @@ var Zotero_File_Interface = new function() {
 	/*
 	 * Shows bibliography options and creates a bibliography
 	 */
-	function _doBibliographyOptions(name, items) {
+	async function _doBibliographyOptions(name, items) {
 		// make sure at least one item is not a standalone note or attachment
 		var haveRegularItem = false;
 		for (let item of items) {
@@ -779,7 +778,7 @@ var Zotero_File_Interface = new function() {
 			browser.loadURIWithFlags("data:text/html;charset=utf-8,"+encodeURI(bibliography),
 				Components.interfaces.nsIWebNavigation.LOAD_FLAGS_BYPASS_HISTORY, null, "utf-8", null);
 		} else if(io.method == "save-as-html") {
-			var fStream = _saveBibliography(name, "HTML");
+			let fStream = await _saveBibliography(name, "HTML");
 			
 			if(fStream !== false) {			
 				var html = "";
@@ -805,7 +804,7 @@ var Zotero_File_Interface = new function() {
 				fStream.close();
 			}
 		} else if(io.method == "save-as-rtf") {
-			var fStream = _saveBibliography(name, "RTF");
+			let fStream = await _saveBibliography(name, "RTF");
 			if(fStream !== false) {
 				fStream.write(bibliography, bibliography.length);
 				fStream.close();
@@ -814,29 +813,31 @@ var Zotero_File_Interface = new function() {
 	}
 	
 	
-	function _saveBibliography(name, format) {	
+	async function _saveBibliography(name, format) {
 		// saveable bibliography, using a file stream
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-		fp.init(window, "Save Bibliography", nsIFilePicker.modeSave);
+		var fp = new FilePicker();
+		fp.init(window, "Save Bibliography", fp.modeSave);
 		
 		if(format == "RTF") {
 			var extension = "rtf";
 			fp.appendFilter("RTF", "*.rtf");
 		} else {
 			var extension = "html";
-			fp.appendFilters(nsIFilePicker.filterHTML);
+			fp.appendFilters(fp.filterHTML);
 		}
 		
 		fp.defaultString = name+"."+extension;
 		
-		var rv = fp.show();
-		if (rv == nsIFilePicker.returnOK || rv == nsIFilePicker.returnReplace) {				
+		var rv = await fp.show();
+		if (rv == fp.returnOK || rv == fp.returnReplace) {
 			// open file
 			var fStream = Components.classes["@mozilla.org/network/file-output-stream;1"].
 						  createInstance(Components.interfaces.nsIFileOutputStream);
-			fStream.init(fp.file, 0x02 | 0x08 | 0x20, 0o664, 0); // write, create, truncate
+			fStream.init(
+				Zotero.File.pathToFile(fp.file),
+				0x02 | 0x08 | 0x20, 0o664, // write, create, truncate
+				0
+			);
 			return fStream;
 		} else {
 			return false;
diff --git a/chrome/content/zotero/import/importWizard.js b/chrome/content/zotero/import/importWizard.js
index facb7d0d45..559d8e8a9e 100644
--- a/chrome/content/zotero/import/importWizard.js
+++ b/chrome/content/zotero/import/importWizard.js
@@ -1,3 +1,5 @@
+import FilePicker from 'zotero/filePicker';
+
 var Zotero_Import_Wizard = {
 	_wizard: null,
 	_dbs: null,
@@ -95,12 +97,10 @@ var Zotero_Import_Wizard = {
 	chooseFile: async function (translation) {
 		var translation = new Zotero.Translate.Import();
 		var translators = await translation.getTranslators();
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString("fileInterface.import"), nsIFilePicker.modeOpen);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString("fileInterface.import"), fp.modeOpen);
 		
-		fp.appendFilters(nsIFilePicker.filterAll);
+		fp.appendFilters(fp.filterAll);
 		
 		var collation = Zotero.getLocaleCollation();
 		
@@ -117,14 +117,14 @@ var Zotero_Import_Wizard = {
 			fp.appendFilter(filter.label, "*." + filter.target);
 		}
 		
-		var rv = fp.show();
-		if (rv !== nsIFilePicker.returnOK && rv !== nsIFilePicker.returnReplace) {
+		var rv = await fp.show();
+		if (rv !== fp.returnOK && rv !== fp.returnReplace) {
 			return false;
 		}
 		
-		Zotero.debug(`File is ${fp.file.path}`);
+		Zotero.debug(`File is ${fp.file}`);
 		
-		this._file = fp.file.path;
+		this._file = fp.file;
 		this._wizard.canAdvance = true;
 		this._wizard.goTo('page-options');
 	},
@@ -151,16 +151,14 @@ var Zotero_Import_Wizard = {
 	 */
 	chooseMendeleyDB: async function () {
 		document.getElementById('file-list').selectedIndex = -1;
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-			.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString('fileInterface.import'), nsIFilePicker.modeOpen);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString('fileInterface.import'), fp.modeOpen);
 		fp.appendFilter("Mendeley Database", "*.sqlite"); // TODO: Localize
-		var rv = fp.show();
-		if (rv != nsIFilePicker.returnOK) {
+		var rv = await fp.show();
+		if (rv != fp.returnOK) {
 			return false;
 		}
-		this._file = fp.file.path;
+		this._file = fp.file;
 		this._wizard.canAdvance = true;
 		this._wizard.advance();
 	},
diff --git a/chrome/content/zotero/modules/filePicker.js b/chrome/content/zotero/modules/filePicker.js
new file mode 100644
index 0000000000..828dd7801a
--- /dev/null
+++ b/chrome/content/zotero/modules/filePicker.js
@@ -0,0 +1,201 @@
+import { Cc, Ci, Cu } from 'chrome';
+Cu.import("resource://gre/modules/osfile.jsm");
+
+/**
+ * Interface to the system filepicker.
+ *
+ * Based on Mozilla's nsIFilePicker, with minor modifications (e.g., strings paths instead nsIFile,
+ * promise-returning show()).
+ *
+ * @class
+ */
+class FilePicker {
+	constructor() {
+		this._fp = Cc["@mozilla.org/filepicker;1"].createInstance(Ci.nsIFilePicker);
+	}
+	
+	/**
+	 * @param {Window} parentWindow
+	 * @param {String} title
+	 * @param {Integer} mode - One of the mode constants, indicating the type of picker to create
+	 */
+	init(parentWindow, title, mode) {
+		this._fp.init(parentWindow, title, mode);
+	};
+	
+	/**
+	 * Appends a custom file extension filter to the dialog. The filter appended first will be used when
+	 * the dialog is initially opened. The user may then select another from the list.
+	 *
+	 * @param {String} title - The title of the filter
+	 * @param {String} filter - The filter string. Multiple extensions may be included, separated by a
+	 *   semicolon and a space.
+	 */
+	appendFilter(title, filter) {
+		this._fp.appendFilter(title, filter);
+	};
+	
+	/**
+	 * Appends a list of file extension filters, from the predefined list, to the dialog
+	 *
+	 * @param {Integer} filterMask - A combination of the filters you wish to use. You may OR multiple
+	 *   filters together; for example <code>filterAll | filterHTML</code>.
+	 */
+	appendFilters(filterMask) {
+		this._fp.appendFilters(filterMask);
+	};
+	
+	/**
+	 * Show the dialog
+	 *
+	 * @return {Promise<Integer>} One of the return constants
+	 */
+	async show() {
+		return new Zotero.Promise(function (resolve) {
+			this._fp.open(returnConstant => resolve(returnConstant));
+		}.bind(this));
+	};
+};
+
+
+/** @const {Integer} FilePicker#modeOpen - Load a file */
+/** @const {Integer} FilePicker#modeSave - Save a file */
+/** @const {Integer} FilePicker#modeGetFolder - Select a folder/directory */
+/** @const {Integer} FilePicker#modeOpenMultiple - Load multiple files */
+FilePicker.prototype.modeOpen = 0;
+FilePicker.prototype.modeSave = 1;
+FilePicker.prototype.modeGetFolder = 2;
+FilePicker.prototype.modeOpenMultiple = 3;
+
+/** @const {Integer} FilePicker#returnOK - The file picker dialog was closed by the user hitting 'OK' */
+/** @const {Integer} FilePicker#returnCancel - The file picker dialog was closed by the user hitting 'Cancel' */
+/** @const {Integer} FilePicker#returnReplace - The user chose an existing file and acknowledged that they want to overwrite the file */
+FilePicker.prototype.returnOK = 0;
+FilePicker.prototype.returnCancel = 1;
+FilePicker.prototype.returnReplace = 2;
+
+/** @const {Integer} FilePicker#filterAll - All files */
+/** @const {Integer} FilePicker#filterHTML - HTML files */
+/** @const {Integer} FilePicker#filterText - Text files */
+/** @const {Integer} FilePicker#filterImages - Image files */
+/** @const {Integer} FilePicker#filterXML - XML files */
+/** @const {Integer} FilePicker#filterApps - Platform-specific application filter */
+/** @const {Integer} FilePicker#filterAllowURLs - Allow URLs */
+/** @const {Integer} FilePicker#filterAudio - Audio files */
+/** @const {Integer} FilePicker#filterVideo - Video files */
+FilePicker.prototype.filterAll = 0x001;
+FilePicker.prototype.filterHTML = 0x002;
+FilePicker.prototype.filterText = 0x004;
+FilePicker.prototype.filterImages = 0x008;
+FilePicker.prototype.filterXML = 0x010;
+FilePicker.prototype.filterApps = 0x040;
+FilePicker.prototype.filterAllowURLs = 0x80;
+FilePicker.prototype.filterAudio = 0x100;
+FilePicker.prototype.filterVideo = 0x200;
+
+['addToRecentDocs', 'defaultExtension', 'defaultString', 'displayDirectory', 'filterIndex'].forEach((prop) => {
+	/**
+	 * @name FilePicker#addToRecentDocs
+	 * @type Boolean
+	 * @default false
+	 * @desc If true, the file is added to the operating system's "recent documents" list (if the
+	 *   operating system has one; nothing happens if there is no such concept on the user's platform).
+	 */
+	/**
+	 * @name FilePicker#defaultExtension
+	 * @type String
+	 * @desc The extension for the type of files you want to work with. On some platforms, this is
+	 *   automatically appended to filenames the user enters, if required.  Specify it without a
+	 *   leading dot, for example "jpg".
+	 */
+	/**
+	 * @name FilePicker#defaultString
+	 * @type String
+	 * @desc The filename, including extension, that should be suggested to the user as a default.
+	 *   This should be set before calling show().
+	*/
+	/**
+	 * @name FilePicker#displayDirectory
+	 * @type String
+	 * @desc The filename, including extension, that should be suggested to the user as a default.
+	 *   This should be set before calling show().
+	 */
+	/**
+	 * @name FilePicker#filterIndex
+	 * @type Integer
+	 * @desc The (0-based) index of the filter which is currently selected in the file picker dialog.
+	 *   Set this to choose a particular filter to be selected by default.
+	 */
+	Object.defineProperty(FilePicker.prototype, prop, {
+		// TODO: Others
+		get: function () {
+			var val = this._fp[prop];
+			if (prop == 'displayDirectory') {
+				// Convert from nsIFile
+				val = val.path;
+			}
+			return val;
+		},
+		set: function (val) {
+			if (prop == 'displayDirectory') {
+				// Convert to nsIFile
+				val = Zotero.File.pathToFile(val);
+			}
+			this._fp[prop] = val;
+		},
+		enumerable: true
+	});
+});
+
+// Read-only properties
+['file', 'files', 'fileURL'].forEach((prop) => {
+	/**
+	 * @name FilePicker#file
+	 * @type String
+	 * @readonly
+	 * @desc The selected file or directory.
+	 */
+	/**
+	 * @name FilePicker#files
+	 * @type String[]
+	 * @readonly
+	 * @desc An array of the selected files. Only works with `modeOpenMultiple` mode.
+	 */
+	/**
+	 * @name FilePicker#fileURL
+	 * @type String
+	 * @readonly
+	 * @desc The URI of the selected file or directory.
+	 */
+	Object.defineProperty(FilePicker.prototype, prop, {
+		get: function () {
+			var val = this._fp[prop];
+			switch (prop) {
+				case 'file':
+					// Convert from nsIFile
+					val = OS.Path.normalize(val.path);
+					break;
+				
+				case 'files':
+					var files = [];
+					while (val.hasMoreElements()) {
+						let file = val.getNext();
+						file.QueryInterface(Ci.nsIFile);
+						files.push(file.path);
+					}
+					val = files;
+					break;
+				
+				case 'fileURL':
+					val = val.spec;
+					break;
+			}
+			return val;
+		},
+		enumerable: true
+	});
+});
+
+Object.freeze(FilePicker.prototype);
+
+export default FilePicker;
\ No newline at end of file
diff --git a/chrome/content/zotero/preferences/preferences_advanced.js b/chrome/content/zotero/preferences/preferences_advanced.js
index 4e7d507bcc..4478d94737 100644
--- a/chrome/content/zotero/preferences/preferences_advanced.js
+++ b/chrome/content/zotero/preferences/preferences_advanced.js
@@ -24,6 +24,7 @@
 */
 
 Components.utils.import("resource://gre/modules/Services.jsm");
+import FilePicker from 'zotero/filePicker';
 
 Zotero_Preferences.Advanced = {
 	_openURLResolvers: null,
@@ -554,25 +555,20 @@ Zotero_Preferences.Attachment_Base_Directory = {
 	},
 	
 	
-	choosePath: Zotero.Promise.coroutine(function* () {
+	choosePath: async function () {
 		var oldPath = this.getPath();
 		
 		//Prompt user to choose new base path
+		var fp = new FilePicker();
 		if (oldPath) {
-			var oldPathFile = Zotero.File.pathToFile(oldPath);
+			fp.displayDirectory = oldPath;
 		}
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-					.createInstance(nsIFilePicker);
-		if (oldPathFile) {
-			fp.displayDirectory = oldPathFile;
-		}
-		fp.init(window, Zotero.getString('attachmentBasePath.selectDir'), nsIFilePicker.modeGetFolder);
-		fp.appendFilters(nsIFilePicker.filterAll);
-		if (fp.show() != nsIFilePicker.returnOK) {
+		fp.init(window, Zotero.getString('attachmentBasePath.selectDir'), fp.modeGetFolder);
+		fp.appendFilters(fp.filterAll);
+		if (await fp.show() != fp.returnOK) {
 			return false;
 		}
-		var newPath = OS.Path.normalize(fp.file.path);
+		var newPath = fp.file;
 		
 		if (oldPath && oldPath == newPath) {
 			Zotero.debug("Base directory hasn't changed");
@@ -580,7 +576,7 @@ Zotero_Preferences.Attachment_Base_Directory = {
 		}
 		
 		return this.changePath(newPath);
-	}),
+	},
 	
 	
 	changePath: Zotero.Promise.coroutine(function* (basePath) {
diff --git a/chrome/content/zotero/preferences/preferences_cite.js b/chrome/content/zotero/preferences/preferences_cite.js
index 8a032b69f3..cc4590918b 100644
--- a/chrome/content/zotero/preferences/preferences_cite.js
+++ b/chrome/content/zotero/preferences/preferences_cite.js
@@ -25,6 +25,8 @@
 
 "use strict";
 
+import FilePicker from 'zotero/filePicker';
+
 Zotero_Preferences.Cite = {
 	wordPluginIDs: new Set([
 		'zoteroOpenOfficeIntegration@zotero.org',
@@ -133,21 +135,27 @@ Zotero_Preferences.Cite = {
 	/**
 	 * Adds a new style to the style pane
 	 **/
-	addStyle: function () {	
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString("zotero.preferences.styles.addStyle"), nsIFilePicker.modeOpen);
+	addStyle: async function () {
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString("zotero.preferences.styles.addStyle"), fp.modeOpen);
 		
 		fp.appendFilter("CSL Style", "*.csl");
 		
-		var rv = fp.show();
-		if (rv == nsIFilePicker.returnOK || rv == nsIFilePicker.returnReplace) {
-			Zotero.Styles.install({ file: fp.file }, fp.file.path, true)
-			.catch(function (e) {
+		var rv = await fp.show();
+		if (rv == fp.returnOK || rv == fp.returnReplace) {
+			try {
+				await Zotero.Styles.install(
+					{
+						file: Zotero.File.pathToFile(fp.file)
+					},
+					fp.file,
+					true
+				);
+			}
+			catch (e) {
 				(new Zotero.Exception.Alert("styles.install.unexpectedError",
-					fp.file.path, "styles.install.title", e)).present()
-			});
+					fp.file, "styles.install.title", e)).present()
+			}
 		}
 	},
 	
diff --git a/chrome/content/zotero/preferences/preferences_general.js b/chrome/content/zotero/preferences/preferences_general.js
index 73c261fa63..83049e3015 100644
--- a/chrome/content/zotero/preferences/preferences_general.js
+++ b/chrome/content/zotero/preferences/preferences_general.js
@@ -27,6 +27,7 @@
 
 Components.utils.import("resource://gre/modules/Services.jsm");
 Components.utils.import("resource://gre/modules/osfile.jsm");
+import FilePicker from 'zotero/filePicker';
 
 Zotero_Preferences.General = {
 	init: function () {
@@ -51,28 +52,25 @@ Zotero_Preferences.General = {
 	//
 	// File handlers
 	//
-	chooseFileHandler: function (type) {
+	chooseFileHandler: async function (type) {
 		var pref = this._getFileHandlerPref(type);
 		var currentPath = Zotero.Prefs.get(pref);
 		
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-			.createInstance(nsIFilePicker);
+		var fp = new FilePicker();
 		if (currentPath) {
-			fp.displayDirectory = Zotero.File.pathToFile(OS.Path.dirname(currentPath));
+			fp.displayDirectory = OS.Path.dirname(currentPath);
 		}
 		fp.init(
 			window,
 			Zotero.getString('zotero.preferences.chooseApplication'),
-			nsIFilePicker.modeOpen
+			fp.modeOpen
 		);
-		fp.appendFilters(nsIFilePicker.filterApps);
-		if (fp.show() != nsIFilePicker.returnOK) {
+		fp.appendFilters(fp.filterApps);
+		if (await fp.show() != fp.returnOK) {
 			this._updateFileHandlerUI();
 			return false;
 		}
-		var newPath = OS.Path.normalize(fp.file.path);
-		this.setFileHandler(type, newPath);
+		this.setFileHandler(type, fp.file);
 	},
 	
 	setFileHandler: function (type, handler) {
diff --git a/chrome/content/zotero/rtfScan.js b/chrome/content/zotero/rtfScan.js
index 612b3babc5..d6530b6480 100644
--- a/chrome/content/zotero/rtfScan.js
+++ b/chrome/content/zotero/rtfScan.js
@@ -26,8 +26,9 @@
 /**
  * @fileOverview Tools for automatically retrieving a citation for the given PDF
  */
- 
- 
+
+import FilePicker from 'zotero/filePicker';
+
 /**
  * Front end for recognizing PDFs
  * @namespace
@@ -73,19 +74,17 @@ var Zotero_RTFScan = new function() {
 	/**
 	 * Called to select the file to be processed
 	 */
-	this.chooseInputFile = function() {
+	this.chooseInputFile = async function () {
 		// display file picker
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString("rtfScan.openTitle"), nsIFilePicker.modeOpen);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString("rtfScan.openTitle"), fp.modeOpen);
 		
-		fp.appendFilters(nsIFilePicker.filterAll);
+		fp.appendFilters(fp.filterAll);
 		fp.appendFilter(Zotero.getString("rtfScan.rtf"), "*.rtf");
 		
-		var rv = fp.show();
-		if (rv == nsIFilePicker.returnOK || rv == nsIFilePicker.returnReplace) {
-			inputFile = fp.file;
+		var rv = await fp.show();
+		if (rv == fp.returnOK || rv == fp.returnReplace) {
+			inputFile = Zotero.File.pathToFile(fp.file);
 			_updatePath();
 		}
 	}
@@ -93,11 +92,9 @@ var Zotero_RTFScan = new function() {
 	/**
 	 * Called to select the output file
 	 */
-	this.chooseOutputFile = function() {
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString("rtfScan.saveTitle"), nsIFilePicker.modeSave);
+	this.chooseOutputFile = async function () {
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString("rtfScan.saveTitle"), fp.modeSave);
 		fp.appendFilter(Zotero.getString("rtfScan.rtf"), "*.rtf");
 		if(inputFile) {
 			var leafName = inputFile.leafName;
@@ -110,9 +107,9 @@ var Zotero_RTFScan = new function() {
 			fp.defaultString = "Untitled.rtf";
 		}
 		
-		var rv = fp.show();
-		if (rv == nsIFilePicker.returnOK || rv == nsIFilePicker.returnReplace) {				
-			outputFile = fp.file;
+		var rv = await fp.show();
+		if (rv == fp.returnOK || rv == fp.returnReplace) {
+			outputFile = Zotero.File.pathToFile(fp.file);
 			_updatePath();
 		}
 	}
diff --git a/chrome/content/zotero/tools/build_typeSchemaData.html b/chrome/content/zotero/tools/build_typeSchemaData.html
index 6f38bd3bb0..b75652d460 100644
--- a/chrome/content/zotero/tools/build_typeSchemaData.html
+++ b/chrome/content/zotero/tools/build_typeSchemaData.html
@@ -7,12 +7,14 @@
 <p id="result"></p>
 <script src="../include.js"></script>
 <script type="text/javascript">
-	Zotero.Promise.coroutine(function* (){
+	import FilePicker from 'zotero/filePicker';
+	
+	(async function () {
 		// Create schema
 		var schema = {"itemTypes":{}, "creatorTypes":{}, "fields":{}};
 		var types = Zotero.ItemTypes.getTypes();
 
-		var fieldIDs = yield Zotero.DB.columnQueryAsync("SELECT fieldID FROM fieldsCombined");
+		var fieldIDs = await Zotero.DB.columnQueryAsync("SELECT fieldID FROM fieldsCombined");
 		var baseMappedFields = Zotero.ItemFields.getBaseMappedFields();
 		
 		for (let fieldID of fieldIDs) {
@@ -70,19 +72,20 @@
 		}
 
 		// Write to file
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-			.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString('dataDir.selectDir'), nsIFilePicker.modeGetFolder);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString('dataDir.selectDir'), fp.modeGetFolder);
 		
 		let resultElem = document.getElementById('result');
-		if (fp.show() != nsIFilePicker.returnOK) {
+		if (await fp.show() != fp.returnOK) {
 			result.innerHTML = '<p>Failed.</p>';
 		} else {
 			let schemaFile = fp.file;
 			schemaFile.append("connectorTypeSchemaData.js");
-			Zotero.File.putContents(schemaFile, `Zotero.Connector_Types.schema = ${JSON.stringify(schema)}`);
-			result.innerHTML = `<p>Wrote ${schemaFile.path} successfully.</p>`;
+			await Zotero.File.putContentsAsync(
+				schemaFile,
+				`Zotero.Connector_Types.schema = ${JSON.stringify(schema)}`
+			);
+			result.innerHTML = `<p>Wrote ${schemaFile} successfully.</p>`;
 		}
 	})();
 </script>
diff --git a/chrome/content/zotero/tools/csledit.js b/chrome/content/zotero/tools/csledit.js
index cd57d9dddf..84779836f8 100644
--- a/chrome/content/zotero/tools/csledit.js
+++ b/chrome/content/zotero/tools/csledit.js
@@ -23,6 +23,8 @@
     ***** END LICENSE BLOCK *****
 */
 
+import FilePicker from 'zotero/filePicker';
+
 var Zotero_CSL_Editor = new function() {
 	this.init = init;
 	this.handleKeyPress = handleKeyPress;
@@ -83,13 +85,11 @@ var Zotero_CSL_Editor = new function() {
 		this.generateBibliography(this.loadStyleFromEditor());
 	}
 	
-	this.save = function() {
+	this.save = async function () {
 		var editor = document.getElementById('zotero-csl-editor');
 		var style = editor.value;
-		const nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-			.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString('styles.editor.save'), nsIFilePicker.modeSave);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString('styles.editor.save'), fp.modeSave);
 		fp.appendFilter("Citation Style Language", "*.csl");
 		//get the filename from the id; we could consider doing even more here like creating the id from filename. 
 		var parser = new DOMParser();
@@ -102,10 +102,10 @@ var Zotero_CSL_Editor = new function() {
 		else {
 			fp.defaultString = "untitled.csl";
 		}
-		var rv = fp.show();
-		if (rv == nsIFilePicker.returnOK || rv == nsIFilePicker.returnReplace) {				
-			var outputFile = fp.file;
-			Zotero.File.putContents(outputFile, style);
+		var rv = await fp.show();
+		if (rv == fp.returnOK || rv == fp.returnReplace) {
+			let outputFile = fp.file;
+			Zotero.File.putContentsAsync(outputFile, style);
 		}
 	};
 	
diff --git a/chrome/content/zotero/xpcom/dataDirectory.js b/chrome/content/zotero/xpcom/dataDirectory.js
index c0ca29c5b7..ca8e6663cb 100644
--- a/chrome/content/zotero/xpcom/dataDirectory.js
+++ b/chrome/content/zotero/xpcom/dataDirectory.js
@@ -25,6 +25,8 @@
 
 "use strict";
 
+import FilePicker from 'zotero/filePicker';
+
 Zotero.DataDirectory = {
 	MIGRATION_MARKER: 'migrate-dir',
 	
@@ -439,7 +441,7 @@ Zotero.DataDirectory = {
 	},
 	
 	
-	choose: Zotero.Promise.coroutine(function* (forceQuitNow, useHomeDir, moreInfoCallback) {
+	choose: async function (forceQuitNow, useHomeDir, moreInfoCallback) {
 		var win = Services.wm.getMostRecentWindow('navigator:browser');
 		var ps = Services.prompt;
 		
@@ -450,17 +452,13 @@ Zotero.DataDirectory = {
 			}
 		}
 		else {
-			var nsIFilePicker = Components.interfaces.nsIFilePicker;
 			while (true) {
-				var fp = Components.classes["@mozilla.org/filepicker;1"]
-							.createInstance(nsIFilePicker);
-				fp.init(win, Zotero.getString('dataDir.selectDir'), nsIFilePicker.modeGetFolder);
-				fp.displayDirectory = Zotero.File.pathToFile(
-					this._dir ? this._dir : OS.Path.dirname(this.defaultDir)
-				);
-				fp.appendFilters(nsIFilePicker.filterAll);
-				if (fp.show() == nsIFilePicker.returnOK) {
-					var file = fp.file;
+				let fp = new FilePicker();
+				fp.init(win, Zotero.getString('dataDir.selectDir'), fp.modeGetFolder);
+				fp.displayDirectory = this._dir ? this._dir : OS.Path.dirname(this.defaultDir);
+				fp.appendFilters(fp.filterAll);
+				if (await fp.show() == fp.returnOK) {
+					let file = Zotero.File.pathToFile(fp.file);
 					let dialogText = '';
 					let dialogTitle = '';
 					
@@ -547,24 +545,22 @@ Zotero.DataDirectory = {
 		}
 		
 		return useHomeDir ? true : file;
-	}),
+	},
 	
 	
-	forceChange: function (win) {
+	forceChange: async function (win) {
 		if (!win) {
 			win = Services.wm.getMostRecentWindow('navigator:browser');
 		}
 		var ps = Services.prompt;
 		
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
 		while (true) {
-			var fp = Components.classes["@mozilla.org/filepicker;1"]
-						.createInstance(nsIFilePicker);
-			fp.init(win, Zotero.getString('dataDir.selectNewDir', Zotero.clientName), nsIFilePicker.modeGetFolder);
-			fp.displayDirectory = Zotero.File.pathToFile(this.dir);
-			fp.appendFilters(nsIFilePicker.filterAll);
-			if (fp.show() == nsIFilePicker.returnOK) {
-				var file = fp.file;
+			let fp = new FilePicker();
+			fp.init(win, Zotero.getString('dataDir.selectNewDir', Zotero.clientName), fp.modeGetFolder);
+			fp.displayDirectory = this.dir;
+			fp.appendFilters(fp.filterAll);
+			if (await fp.show() == fp.returnOK) {
+				let file = Zotero.File.pathToFile(fp.file);
 				
 				if (file.directoryEntries.hasMoreElements()) {
 					ps.alert(null,
diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index 77ac3c6d9c..a045d6641b 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -23,6 +23,8 @@
     ***** END LICENSE BLOCK *****
 */
 
+import FilePicker from 'zotero/filePicker';
+
 /*
  * This object contains the various functions for the interface
  */
@@ -955,16 +957,15 @@ var ZoteroPane = new function()
 		return collection.saveTx();
 	});
 	
-	this.importFeedsFromOPML = Zotero.Promise.coroutine(function* (event) {
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
+	this.importFeedsFromOPML = async function (event) {
 		while (true) {
-			var fp = Components.classes["@mozilla.org/filepicker;1"].createInstance(nsIFilePicker);
-			fp.init(window, Zotero.getString('fileInterface.importOPML'), nsIFilePicker.modeOpen);
+			let fp = new FilePicker();
+			fp.init(window, Zotero.getString('fileInterface.importOPML'), fp.modeOpen);
 			fp.appendFilter(Zotero.getString('fileInterface.OPMLFeedFilter'), '*.opml; *.xml');
-			fp.appendFilters(nsIFilePicker.filterAll);
-			if (fp.show() == nsIFilePicker.returnOK) {
-				var contents = yield Zotero.File.getContentsAsync(fp.file.path);
-				var success = yield Zotero.Feeds.importFromOPML(contents);
+			fp.appendFilters(fp.filterAll);
+			if (await fp.show() == fp.returnOK) {
+				var contents = await Zotero.File.getContentsAsync(fp.file.path);
+				var success = await Zotero.Feeds.importFromOPML(contents);
 				if (success) {
 					return true;
 				}
@@ -974,7 +975,7 @@ var ZoteroPane = new function()
 				return false;
 			}
 		}
-	});
+	};
 	
 	
 	this.newFeedFromURL = Zotero.Promise.coroutine(function* () {
@@ -3579,7 +3580,7 @@ var ZoteroPane = new function()
 	});
 	
 	
-	this.addAttachmentFromDialog = Zotero.Promise.coroutine(function* (link, parentItemID) {
+	this.addAttachmentFromDialog = async function (link, parentItemID) {
 		if (!this.canEdit()) {
 			this.displayCannotEditLibraryMessage();
 			return;
@@ -3609,24 +3610,15 @@ var ZoteroPane = new function()
 		
 		var libraryID = collectionTreeRow.ref.libraryID;
 		
-		var nsIFilePicker = Components.interfaces.nsIFilePicker;
-		var fp = Components.classes["@mozilla.org/filepicker;1"]
-        					.createInstance(nsIFilePicker);
-		fp.init(window, Zotero.getString('pane.item.attachments.select'), nsIFilePicker.modeOpenMultiple);
-		fp.appendFilters(nsIFilePicker.filterAll);
+		var fp = new FilePicker();
+		fp.init(window, Zotero.getString('pane.item.attachments.select'), fp.modeOpenMultiple);
+		fp.appendFilters(fp.filterAll);
 		
-		if (fp.show() != nsIFilePicker.returnOK) {
+		if (await fp.show() != fp.returnOK) {
 			return;
 		}
 		
-		var enumerator = fp.files;
-		var files = [];
-		while (enumerator.hasMoreElements()) {
-			let file = enumerator.getNext();
-			file.QueryInterface(Components.interfaces.nsIFile);
-			files.push(file.path);
-		}
-		
+		var files = fp.files;
 		var addedItems = [];
 		var collection;
 		var fileBaseName;
@@ -3637,7 +3629,7 @@ var ZoteroPane = new function()
 			if (files.length == 1 && Zotero.Attachments.shouldAutoRenameFile(link)) {
 				let parentItem = Zotero.Items.get(parentItemID);
 				if (!parentItem.numNonHTMLFileAttachments()) {
-					fileBaseName = yield Zotero.Attachments.getRenamedFileBaseNameIfAllowedType(
+					fileBaseName = await Zotero.Attachments.getRenamedFileBaseNameIfAllowedType(
 						parentItem, files[0]
 					);
 				}
@@ -3656,7 +3648,7 @@ var ZoteroPane = new function()
 				try {
 					if (fileBaseName) {
 						let ext = Zotero.File.getExtension(file);
-						let newName = yield Zotero.File.rename(
+						let newName = await Zotero.File.rename(
 							file,
 							fileBaseName + (ext ? '.' + ext : ''),
 							{
@@ -3671,7 +3663,7 @@ var ZoteroPane = new function()
 					Zotero.logError(e);
 				}
 				
-				item = yield Zotero.Attachments.linkFromFile({
+				item = await Zotero.Attachments.linkFromFile({
 					file,
 					parentItemID,
 					collections: collection ? [collection] : undefined
@@ -3684,7 +3676,7 @@ var ZoteroPane = new function()
 					continue;
 				}
 				
-				item = yield Zotero.Attachments.importFromFile({
+				item = await Zotero.Attachments.importFromFile({
 					file,
 					libraryID,
 					fileBaseName,
@@ -3700,7 +3692,7 @@ var ZoteroPane = new function()
 		if (!parentItemID) {
 			Zotero.RecognizePDF.autoRecognizeItems(addedItems);
 		}
-	});
+	};
 	
 	
 	this.findPDFForSelectedItems = async function () {
@@ -4643,7 +4635,7 @@ var ZoteroPane = new function()
 	};
 	
 	
-	this.relinkAttachment = Zotero.Promise.coroutine(function* (itemID) {
+	this.relinkAttachment = async function (itemID) {
 		if (!this.canEdit()) {
 			this.displayCannotEditLibraryMessage();
 			return;
@@ -4655,10 +4647,8 @@ var ZoteroPane = new function()
 		}
 		
 		while (true) {
-			var nsIFilePicker = Components.interfaces.nsIFilePicker;
-			var fp = Components.classes["@mozilla.org/filepicker;1"]
-						.createInstance(nsIFilePicker);
-			fp.init(window, Zotero.getString('pane.item.attachments.select'), nsIFilePicker.modeOpen);
+			let fp = new FilePicker();
+			fp.init(window, Zotero.getString('pane.item.attachments.select'), fp.modeOpen);
 			
 			var file = item.getFilePath();
 			if (!file) {
@@ -4666,16 +4656,15 @@ var ZoteroPane = new function()
 				break;
 			}
 			
-			var dir = yield Zotero.File.getClosestDirectory(file);
+			var dir = await Zotero.File.getClosestDirectory(file);
 			if (dir) {
-				fp.displayDirectory = Zotero.File.pathToFile(dir);
+				fp.displayDirectory = dir;
 			}
 			
-			fp.appendFilters(Components.interfaces.nsIFilePicker.filterAll);
+			fp.appendFilters(fp.filterAll);
 			
-			if (fp.show() == nsIFilePicker.returnOK) {
-				let file = fp.file;
-				file.QueryInterface(Components.interfaces.nsILocalFile);
+			if (await fp.show() == fp.returnOK) {
+				let file = Zotero.File.pathToFile(fp.file);
 				
 				// Disallow hidden files
 				// TODO: Display a message
@@ -4689,13 +4678,13 @@ var ZoteroPane = new function()
 					continue;
 				}
 				
-				yield item.relinkAttachmentFile(file.path);
+				await item.relinkAttachmentFile(file.path);
 				break;
 			}
 			
 			break;
 		}
-	});
+	};
 	
 	
 	this.updateReadLabel = function () {
diff --git a/test/tests/syncLocalTest.js b/test/tests/syncLocalTest.js
index 783a1ab03a..c6de6cb666 100644
--- a/test/tests/syncLocalTest.js
+++ b/test/tests/syncLocalTest.js
@@ -80,7 +80,7 @@ describe("Zotero.Sync.Data.Local", function() {
 		
 		// extra1 functionality not used at the moment
 		it.skip("should prompt for data reset and allow to choose a new data directory", function* (){
-			sinon.stub(Zotero.DataDirectory, 'forceChange').returns(true);
+			sinon.stub(Zotero.DataDirectory, 'forceChange').returns(Zotero.Promise.resolve(true));
 			yield Zotero.Users.setCurrentUserID(1);
 			yield Zotero.Users.setCurrentUsername("A");