diff --git a/chrome/content/zotero/xpcom/translation/translate_firefox.js b/chrome/content/zotero/xpcom/translation/translate_firefox.js
index c9cc2acfef..abb66c8dd0 100644
--- a/chrome/content/zotero/xpcom/translation/translate_firefox.js
+++ b/chrome/content/zotero/xpcom/translation/translate_firefox.js
@@ -149,7 +149,8 @@ Zotero.Translate.SandboxManager.prototype = {
 	 */
 	"importObject":function(object, passAsFirstArgument, attachTo) {
 		if(!attachTo) attachTo = this.sandbox.Zotero;
-		var newExposedProps = false;
+		var newExposedProps = false,
+			sandbox = this.sandbox;
 		if(!object.__exposedProps__) newExposedProps = {};
 		for(var key in (newExposedProps ? object : object.__exposedProps__)) {
 			let localKey = key;
@@ -160,30 +161,16 @@ Zotero.Translate.SandboxManager.prototype = {
 			var isObject = typeof object[localKey] === "object";
 			if(isFunction || isObject) {
 				if(isFunction) {
-					if(Zotero.isFx4) {
-						if(passAsFirstArgument) {
-							attachTo[localKey] = object[localKey].bind(object, passAsFirstArgument);
-						} else {
-							attachTo[localKey] = object[localKey].bind(object);
+					attachTo[localKey] = function() {
+						var args = Array.prototype.slice.apply(arguments);
+						if(passAsFirstArgument) args.unshift(passAsFirstArgument);
+						var out = object[localKey].apply(object, args);
+						if(out instanceof Array) {
+							// Copy to sandbox
+							out = sandbox.Array.prototype.slice.apply(out);
 						}
-					} else {
-						attachTo[localKey] = function() {
-							if(passAsFirstArgument) {
-								var args = new Array(arguments.length+1);
-								args[0] = passAsFirstArgument;
-								var offset = 1;
-							} else {
-								var args = new Array(arguments.length);
-								var offset = 0;
-							}
-							
-							for(var i=0, nArgs=arguments.length; i<nArgs; i++) {
-								args[i+offset] = arguments[i];
-							}
-							
-							return object[localKey].apply(object, args);
-						};
-					}
+						return out;
+					};
 				} else {
 					attachTo[localKey] = {};
 				}