diff --git a/chrome/content/zotero/xpcom/storage/storageEngine.js b/chrome/content/zotero/xpcom/storage/storageEngine.js
index a5df9c8fa..8c7b99197 100644
--- a/chrome/content/zotero/xpcom/storage/storageEngine.js
+++ b/chrome/content/zotero/xpcom/storage/storageEngine.js
@@ -282,7 +282,7 @@ Zotero.Sync.Storage.Engine.prototype.start = Zotero.Promise.coroutine(function*
 
 
 Zotero.Sync.Storage.Engine.prototype.stop = function () {
-	Zotero.debug("Stopping file syncing for " + this.library.name);
+	Zotero.debug("Stopping file sync for " + this.library.name);
 	for (let type in this.queues) {
 		this.queues[type].stop();
 	}
diff --git a/chrome/content/zotero/xpcom/sync/syncEngine.js b/chrome/content/zotero/xpcom/sync/syncEngine.js
index bee54a371..d74491eff 100644
--- a/chrome/content/zotero/xpcom/sync/syncEngine.js
+++ b/chrome/content/zotero/xpcom/sync/syncEngine.js
@@ -210,7 +210,7 @@ Zotero.Sync.Data.Engine.prototype.start = Zotero.Promise.coroutine(function* ()
  * Stop the sync process
  */
 Zotero.Sync.Data.Engine.prototype.stop = function () {
-	Zotero.debug("Stopping sync for " + this.library.name);
+	Zotero.debug("Stopping data sync for " + this.library.name);
 	this._stopping = true;
 }
 
diff --git a/chrome/content/zotero/xpcom/sync/syncRunner.js b/chrome/content/zotero/xpcom/sync/syncRunner.js
index f1f6184d9..ed5d6e55f 100644
--- a/chrome/content/zotero/xpcom/sync/syncRunner.js
+++ b/chrome/content/zotero/xpcom/sync/syncRunner.js
@@ -79,6 +79,8 @@ Zotero.Sync.Runner_Module = function (options = {}) {
 	var _currentLastSyncLabel;
 	var _errors = [];
 	
+	Zotero.addShutdownListener(() => this.stop());
+	
 	this.getAPIClient = function (options = {}) {
 		return new Zotero.Sync.APIClient({
 			baseURL: this.baseURL,