diff --git a/chrome/content/zotero/xpcom/sync/syncAPIClient.js b/chrome/content/zotero/xpcom/sync/syncAPIClient.js
index 8515ccf007..38aefc0769 100644
--- a/chrome/content/zotero/xpcom/sync/syncAPIClient.js
+++ b/chrome/content/zotero/xpcom/sync/syncAPIClient.js
@@ -46,6 +46,7 @@ Zotero.Sync.APIClient = function (options) {
 Zotero.Sync.APIClient.prototype = {
 	MAX_OBJECTS_PER_REQUEST: 100,
 	MIN_GZIP_SIZE: 1000,
+	UPLOAD_TIMEOUT: 60,
 	
 	
 	getKeyInfo: Zotero.Promise.coroutine(function* (options={}) {
@@ -379,7 +380,8 @@ Zotero.Sync.APIClient.prototype = {
 				"If-Unmodified-Since-Version": libraryVersion
 			},
 			body: json,
-			successCodes: [200, 412]
+			successCodes: [200, 412],
+			timeout: this.UPLOAD_TIMEOUT,
 		});
 		this._check412(xmlhttp);
 		return {
@@ -413,7 +415,8 @@ Zotero.Sync.APIClient.prototype = {
 			headers: {
 				"If-Unmodified-Since-Version": libraryVersion
 			},
-			successCodes: [204, 412]
+			successCodes: [204, 412],
+			timeout: this.UPLOAD_TIMEOUT,
 		});
 		this._check412(xmlhttp);
 		return this._getLastModifiedVersion(xmlhttp);
@@ -481,6 +484,7 @@ Zotero.Sync.APIClient.prototype = {
 				},
 				body: JSON.stringify(data),
 				successCodes: [200, 412],
+				timeout: this.UPLOAD_TIMEOUT,
 				debug: true
 			}
 		);
diff --git a/chrome/content/zotero/xpcom/sync/syncEngine.js b/chrome/content/zotero/xpcom/sync/syncEngine.js
index eb4f530c70..5d746d8d44 100644
--- a/chrome/content/zotero/xpcom/sync/syncEngine.js
+++ b/chrome/content/zotero/xpcom/sync/syncEngine.js
@@ -50,8 +50,8 @@ Zotero.Sync.Data.Engine = function (options) {
 	this.libraryID = options.libraryID;
 	this.library = Zotero.Libraries.get(options.libraryID);
 	this.libraryTypeID = this.library.libraryTypeID;
-	this.uploadBatchSize = 25;
-	this.uploadDeletionBatchSize = 50;
+	this.uploadBatchSize = 10;
+	this.uploadDeletionBatchSize = 25;
 	this.maxUploadTries = 5;
 	
 	this.failed = false;