diff --git a/chrome/content/zotero/xpcom/schema.js b/chrome/content/zotero/xpcom/schema.js
index 2d8b4dc75..7686271a4 100644
--- a/chrome/content/zotero/xpcom/schema.js
+++ b/chrome/content/zotero/xpcom/schema.js
@@ -131,9 +131,8 @@ Zotero.Schema = new function(){
 			// If upgrading userdata, make backup of database first
 			if (dbVersion < schemaVersion){
 				Zotero.DB.backupDatabase(dbVersion);
-			}
-			
-			Zotero.wait(1000);
+				Zotero.wait(1000);
+			}			
 			
 			Zotero.DB.beginTransaction();
 			
@@ -159,14 +158,14 @@ Zotero.Schema = new function(){
 				if (Zotero.DB.tableExists('customItemTypes')) {
 					this.updateCustomTables(up2);
 				}
-				Zotero.wait();
+				if(up2) Zotero.wait();
 				var up1 = _migrateUserDataSchema(dbVersion);
 				var up3 = _updateSchema('triggers');
 				// Update custom tables again in case custom fields were changed during user data migration
 				if (up1) {
 					this.updateCustomTables();
 				}
-				Zotero.wait();
+				if(up1) Zotero.wait();
 				
 				Zotero.DB.commitTransaction();
 			}