diff --git a/chrome/content/zotero/xpcom/data/dataObjects.js b/chrome/content/zotero/xpcom/data/dataObjects.js
index 3907bedfe..38f3df535 100644
--- a/chrome/content/zotero/xpcom/data/dataObjects.js
+++ b/chrome/content/zotero/xpcom/data/dataObjects.js
@@ -460,7 +460,7 @@ Zotero.DataObjects.prototype.updateVersion = Zotero.Promise.method(function (ids
 	return Zotero.Utilities.Internal.forEachChunkAsync(
 		ids,
 		Zotero.DB.MAX_BOUND_PARAMETERS,
-		function* (chunk) {
+		Zotero.Promise.coroutine(function* (chunk) {
 			yield Zotero.DB.queryAsync(sql + chunk.map(() => '?').join(', ') + ')', chunk);
 			// Update the internal 'version' property of any loaded objects
 			for (let i = 0; i < chunk.length; i++) {
@@ -470,7 +470,7 @@ Zotero.DataObjects.prototype.updateVersion = Zotero.Promise.method(function (ids
 					obj.updateVersion(version, true);
 				}
 			}
-		}.bind(this)
+		}.bind(this))
 	);
 });
 
@@ -487,7 +487,7 @@ Zotero.DataObjects.prototype.updateSynced = Zotero.Promise.method(function (ids,
 	return Zotero.Utilities.Internal.forEachChunkAsync(
 		ids,
 		Zotero.DB.MAX_BOUND_PARAMETERS,
-		function* (chunk) {
+		Zotero.Promise.coroutine(function* (chunk) {
 			yield Zotero.DB.queryAsync(sql + chunk.map(() => '?').join(', ') + ')', chunk);
 			// Update the internal 'synced' property of any loaded objects
 			for (let i = 0; i < chunk.length; i++) {
@@ -497,7 +497,7 @@ Zotero.DataObjects.prototype.updateSynced = Zotero.Promise.method(function (ids,
 					obj.updateSynced(!!synced, true);
 				}
 			}
-		}.bind(this)
+		}.bind(this))
 	);
 });
 
diff --git a/chrome/content/zotero/xpcom/data/items.js b/chrome/content/zotero/xpcom/data/items.js
index d003aac4f..b5c99444b 100644
--- a/chrome/content/zotero/xpcom/data/items.js
+++ b/chrome/content/zotero/xpcom/data/items.js
@@ -528,10 +528,10 @@ Zotero.Items = function() {
 		
 		deletedIDs = yield this.getDeleted(libraryID, true, days);
 		if (deletedIDs.length) {
-			yield Zotero.Utilities.Internal.forEachChunkAsync(deletedIDs, 50, function* (chunk) {
+			yield Zotero.Utilities.Internal.forEachChunkAsync(deletedIDs, 50, Zotero.Promise.coroutine(function* (chunk) {
 				yield this.erase(chunk);
 				yield Zotero.Notifier.trigger('refresh', 'trash', libraryID);
-			}.bind(this));
+			}.bind(this)));
 		}
 		
 		if (deletedIDs.length) {
diff --git a/chrome/content/zotero/xpcom/data/tags.js b/chrome/content/zotero/xpcom/data/tags.js
index 137682a00..7ac2b57c6 100644
--- a/chrome/content/zotero/xpcom/data/tags.js
+++ b/chrome/content/zotero/xpcom/data/tags.js
@@ -191,7 +191,7 @@ Zotero.Tags = new function() {
 			yield Zotero.Utilities.Internal.forEachChunkAsync(
 				oldItemIDs,
 				Zotero.DB.MAX_BOUND_PARAMETERS - 2,
-				function* (chunk) {
+				Zotero.Promise.coroutine(function* (chunk) {
 					let placeholders = chunk.map(function () '?').join(',');
 					
 					// This is ugly, but it's much faster than doing replaceTag() for each item
@@ -204,7 +204,7 @@ Zotero.Tags = new function() {
 					yield Zotero.DB.queryAsync(sql, [Zotero.DB.transactionDateTime].concat(chunk));
 					
 					yield Zotero.Items.reload(oldItemIDs, ['tags'], true);
-				}
+				})
 			);
 			
 			var notifierData = {};
@@ -292,7 +292,7 @@ Zotero.Tags = new function() {
 			yield Zotero.Utilities.Internal.forEachChunkAsync(
 				Zotero.Utilities.arrayUnique(oldItemIDs),
 				Zotero.DB.MAX_BOUND_PARAMETERS - 1,
-				function* (chunk) {
+				Zotero.Promise.coroutine(function* (chunk) {
 					let placeholders = chunk.map(function () '?').join(',');
 					
 					sql = 'UPDATE items SET synced=0, clientDateModified=? '
@@ -300,7 +300,7 @@ Zotero.Tags = new function() {
 					yield Zotero.DB.queryAsync(sql, [Zotero.DB.transactionDateTime].concat(chunk));
 					
 					yield Zotero.Items.reload(oldItemIDs, ['primaryData', 'tags'], true);
-				}
+				})
 			);
 		}.bind(this));
 		
diff --git a/chrome/content/zotero/xpcom/utilities_internal.js b/chrome/content/zotero/xpcom/utilities_internal.js
index a507645e8..36907d998 100644
--- a/chrome/content/zotero/xpcom/utilities_internal.js
+++ b/chrome/content/zotero/xpcom/utilities_internal.js
@@ -35,8 +35,7 @@ Zotero.Utilities.Internal = {
 	 *
 	 * @param {Array} arr
 	 * @param {Integer} chunkSize
-	 * @param {Function|GeneratorFunction} func - A promise-returning function or a
-	 *                                            promise-yielding generator
+	 * @param {Function} func - A promise-returning function
 	 * @return {Array} The return values from the successive runs
 	 */
 	"forEachChunkAsync": Zotero.Promise.coroutine(function* (arr, chunkSize, func) {
@@ -45,8 +44,6 @@ Zotero.Utilities.Internal = {
 		var num = arr.length;
 		var done = 0;
 		
-		func = Zotero.Promise.coroutine(func);
-		
 		do {
 			var chunk = tmpArray.splice(0, chunkSize);
 			done += chunk.length;