diff --git a/src/storage/gcs.js b/src/storage/gcs.js
index 552375148..ece3d2ef5 100644
--- a/src/storage/gcs.js
+++ b/src/storage/gcs.js
@@ -115,27 +115,25 @@ function listDir(apiConfig, backupFilePath, batchSize, iteratorCallback, callbac
         query.maxResults = batchSize;
     }
 
-    async.forever(function listAndDownload(foreverCallback) {
-        bucket.getFiles(query, function (error, files, nextQuery) {
-            if (error) return foreverCallback(error);
+    let done = false;
 
-            if (files.length === 0) return foreverCallback(new Error('Done'));
+    async.whilst(() => !done, function listAndDownload(whilstCallback) {
+        bucket.getFiles(query, function (error, files, nextQuery) {
+            if (error) return whilstCallback(error);
+
+            if (files.length === 0) { done = true; return whilstCallback(); }
 
             const entries = files.map(function (f) { return { fullPath: f.name }; });
             iteratorCallback(entries, function (error) {
-                if (error) return foreverCallback(error);
-                if (!nextQuery) return foreverCallback(new Error('Done'));
+                if (error) return whilstCallback(error);
+                if (!nextQuery) { done = true; return whilstCallback(); }
 
                 query = nextQuery;
 
-                foreverCallback();
+                whilstCallback();
             });
         });
-    }, function (error) {
-        if (error.message === 'Done') return callback(null);
-
-        callback(error);
-    });
+    }, callback);
 }
 
 function copy(apiConfig, oldFilePath, newFilePath) {
diff --git a/src/storage/noop.js b/src/storage/noop.js
index bb5073793..988c06f44 100644
--- a/src/storage/noop.js
+++ b/src/storage/noop.js
@@ -17,6 +17,7 @@ exports = module.exports = {
 };
 
 var assert = require('assert'),
+    BoxError = require('../boxerror.js'),
     debug = require('debug')('box:storage/noop'),
     EventEmitter = require('events');
 
@@ -38,7 +39,7 @@ function download(apiConfig, backupFilePath, callback) {
 
     debug('download: %s', backupFilePath);
 
-    callback(new Error('Cannot download from noop backend'));
+    callback(new BoxError(BoxError.NOT_IMPLEMENTED, 'Cannot download from noop backend'));
 }
 
 function listDir(apiConfig, dir, batchSize, iteratorCallback, callback) {
@@ -60,7 +61,7 @@ function downloadDir(apiConfig, backupFilePath, destDir) {
     process.nextTick(function () {
         debug('downloadDir: %s -> %s', backupFilePath, destDir);
 
-        events.emit('done', new Error('Cannot download from noop backend'));
+        events.emit('done', new BoxError(BoxError.NOT_IMPLEMENTED, 'Cannot download from noop backend'));
     });
     return events;
 }
@@ -109,5 +110,6 @@ function removePrivateFields(apiConfig) {
     return apiConfig;
 }
 
+// eslint-disable-next-line no-unused-vars
 function injectPrivateFields(newConfig, currentConfig) {
 }
diff --git a/src/storage/s3.js b/src/storage/s3.js
index 80964040e..3da48523e 100644
--- a/src/storage/s3.js
+++ b/src/storage/s3.js
@@ -161,29 +161,27 @@ function listDir(apiConfig, dir, batchSize, iteratorCallback, callback) {
             MaxKeys: batchSize
         };
 
-        async.forever(function listAndDownload(foreverCallback) {
-            s3.listObjects(listParams, function (error, listData) {
-                if (error) return foreverCallback(error);
+        let done = false;
 
-                if (listData.Contents.length === 0) return foreverCallback(new Error('Done'));
+        async.whilst(() => !done, function listAndDownload(whilstCallback) {
+            s3.listObjects(listParams, function (error, listData) {
+                if (error) return whilstCallback(error);
+
+                if (listData.Contents.length === 0) { done = true; return whilstCallback(); }
 
                 const entries = listData.Contents.map(function (c) { return { fullPath: c.Key, size: c.Size }; });
 
                 iteratorCallback(entries, function (error) {
-                    if (error) return foreverCallback(error);
+                    if (error) return whilstCallback(error);
 
-                    if (!listData.IsTruncated) return foreverCallback(new Error('Done'));
+                    if (!listData.IsTruncated) { done = true; return whilstCallback(); }
 
                     listParams.Marker = listData.Contents[listData.Contents.length - 1].Key; // NextMarker is returned only with delimiter
 
-                    foreverCallback();
+                    whilstCallback();
                 });
             });
-        }, function (error) {
-            if (error.message === 'Done') return callback(null);
-
-            callback(error);
-        });
+        }, callback);
     });
 }