diff --git a/chrome/content/zotero/upgrade.xul b/chrome/content/zotero/upgrade.xul
index a97336148..5a214291b 100644
--- a/chrome/content/zotero/upgrade.xul
+++ b/chrome/content/zotero/upgrade.xul
@@ -14,7 +14,6 @@
 			this.init = init;
 			this.onAdvance = onAdvance;
 			this.doUpgrade = doUpgrade;
-			this.onChangeLogLinkClick = onChangeLogLinkClick;
 			
 			var obj = window.arguments[0].wrappedJSObject;
 			var Zotero = obj.Zotero;
@@ -23,9 +22,18 @@
 			function init() {
 				var wizard = document.getElementById('zotero-schema-upgrade');
 				
-				var continueButtonName = wizard.getButton('next').getAttribute('label');
+				var continueButton = wizard.getButton('next');
+				continueButton.focus(); // prevent focusing upgrade instructions link
+				
+				// Use proper button name in text
+				var continueButtonName = continueButton.getAttribute('label');
 				var str = Zotero.getString('upgrade.advanceMessage', continueButtonName);
 				document.getElementById('zotero-advance-message').setAttribute('value', str);
+				
+				if (data.majorUpgrade) {
+					document.getElementById('zotero-major-upgrade').hidden = false;
+					document.getElementById('zotero-upgrade-required').hidden = true;
+				}
 			}
 			
 			
@@ -45,6 +53,28 @@
 				onAdvance();
 				
 				try {
+					if (data.integrityCheck) {
+						if (!Zotero.DB.integrityCheck()) {
+							var pr = Components.classes["@mozilla.org/network/default-prompt;1"]
+											.createInstance(Components.interfaces.nsIPrompt);
+							var buttonFlags = (pr.BUTTON_POS_0) * (pr.BUTTON_TITLE_IS_STRING)
+												+ (pr.BUTTON_POS_1) * (pr.BUTTON_TITLE_CANCEL);
+							var index = pr.confirmEx(
+								Zotero.getString('general.error'),
+								Zotero.getString('upgrade.integrityCheckFailed'),
+								buttonFlags, Zotero.getString('upgrade.loadDBRepairTool'),
+								null, null, null, {});
+							
+							if (index == 0) {
+								Zotero.initialURL = 'https://www.zotero.org/utils/dbfix/';
+							}
+							
+							_setStartupError();
+							_clickCancel();
+							return;
+						}
+					}
+					
 					Zotero.Schema.updateSchema();
 				}
 				catch (e) {
@@ -53,9 +83,7 @@
 					
 					Components.utils.reportError(e);
 					
-					var cancelButton = wizard.getButton('cancel');
-					cancelButton.setAttribute('disabled', false);
-					cancelButton.click();
+					_clickCancel();
 					return;
 				}
 				
@@ -65,17 +93,45 @@
 			}
 			
 			
-			function onChangeLogLinkClick() {
+			this.onUpgradeInstructionsLinkClick = function () {
+				_setStartupError();
+				Zotero.initialURL = 'http://zotero.org/support/upgrade';
+				_clickCancel();
+			}
+			
+			
+			this.onChangeLogLinkClick = function () {
 				Zotero.initialURL = 'http://zotero.org/support/changelog';
 				document.getElementById('zotero-schema-upgrade').getButton('finish').click();
 			}
+			
+			
+			function _setStartupError() {
+				Zotero.startupError = Zotero.localeJoin([
+					Zotero.getString('upgrade.dbUpdateRequired'), Zotero.getString('general.restartFirefox')
+				]);
+			}
+			
+			
+			function _clickCancel() {
+				var cancelButton = document.getElementById('zotero-schema-upgrade').getButton('cancel');
+				cancelButton.setAttribute('disabled', false);
+				cancelButton.click();
+			}
 		}
 	]]>
 	</script>
 	
 	<wizardpage onpageshow="Zotero_Schema_Upgrade.init()">
 		<description>&zotero.upgrade.newVersionInstalled;</description>
-		<description>&zotero.upgrade.upgradeRequired; &zotero.upgrade.autoBackup;</description>
+		<description id="zotero-upgrade-required">&zotero.upgrade.upgradeRequired; &zotero.upgrade.autoBackup;</description>
+		<description id="zotero-major-upgrade" hidden="true">
+			<label value="&zotero.upgrade.majorUpgrade;" style="font-weight: bold"/>
+			&zotero.upgrade.majorUpgradeBeforeLink;
+			<label class="text-link" value="&zotero.upgrade.majorUpgradeLink;"
+				onclick="try { Zotero_Schema_Upgrade.onUpgradeInstructionsLinkClick(); } catch (e) { alert(e); }"/>
+			&zotero.upgrade.majorUpgradeAfterLink;
+		</description>
 		<description id="zotero-advance-message"/>
 	</wizardpage>
 	
@@ -88,7 +144,7 @@
 		<description>&zotero.upgrade.upgradeSucceeded;</description>
 		<description>
 			&zotero.upgrade.changeLogBeforeLink;
-			<label id="zotero-change-log-link" class="text-link" value="&zotero.upgrade.changeLogLink;"
+			<label class="text-link" value="&zotero.upgrade.changeLogLink;"
 				onclick="Zotero_Schema_Upgrade.onChangeLogLinkClick()"/>
 			&zotero.upgrade.changeLogAfterLink;
 		</description>
diff --git a/chrome/content/zotero/xpcom/schema.js b/chrome/content/zotero/xpcom/schema.js
index ccc68aa22..79499021a 100644
--- a/chrome/content/zotero/xpcom/schema.js
+++ b/chrome/content/zotero/xpcom/schema.js
@@ -52,9 +52,24 @@ Zotero.Schema = new function(){
 		var dbVersion = _getDBVersion('userdata');
 		var schemaVersion = _getSchemaSQLVersion('userdata');
 		
+		// Upgrading from 1.0 or earlier
+		if (dbVersion <= 36) {
+			var integrityCheck = true;
+			var majorUpgrade = true;
+		}
+		else {
+			var integrityCheck = false;
+			var majorUpgrade = false;
+		}
+		
 		var ww = Components.classes["@mozilla.org/embedcomp/window-watcher;1"]
-				   .getService(Components.interfaces.nsIWindowWatcher);
-		var obj = { Zotero: Zotero, data: { success: false } };
+					.getService(Components.interfaces.nsIWindowWatcher);
+		var data = {
+			success: false,
+			majorUpgrade: majorUpgrade,
+			integrityCheck: integrityCheck
+		};
+		var obj = { Zotero: Zotero, data: data };
 		var io = { wrappedJSObject: obj };
 		var win = ww.openWindow(null, "chrome://zotero/content/upgrade.xul",
 					"zotero-schema-upgrade", "chrome,centerscreen,modal", io);
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index fb5c03212..43459c2fa 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -71,7 +71,7 @@ var Zotero = new function(){
 	// Public properties
 	this.initialized = false;
 	this.skipLoading = false;
-	this.__defineGetter__("startupError", function() { return _startupError; });
+	this.startupError;
 	this.__defineGetter__("startupErrorHandler", function() { return _startupErrorHandler; });
 	this.version;
 	this.platform;
@@ -146,7 +146,6 @@ var Zotero = new function(){
 	 */
 	this.__defineGetter__('locked', function () _locked);
 	
-	var _startupError;
 	var _startupErrorHandler;
 	var _zoteroDirectory = false;
 	var _localizedStringBundle;
@@ -255,7 +254,7 @@ var Zotero = new function(){
 		catch (e) {
 			// Zotero dir not found
 			if (e.name == 'NS_ERROR_FILE_NOT_FOUND') {
-				_startupError = Zotero.getString('dataDir.notFound');
+				this.startupError = Zotero.getString('dataDir.notFound');
 				_startupErrorHandler = function() {
 					var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
 						.getService(Components.interfaces.nsIWindowMediator);
@@ -268,7 +267,7 @@ var Zotero = new function(){
 						+ (ps.BUTTON_POS_2) * (ps.BUTTON_TITLE_IS_STRING);
 					var index = ps.confirmEx(win,
 						Zotero.getString('general.error'),
-						_startupError + '\n\n' +
+						this.startupError + '\n\n' +
 						Zotero.getString('dataDir.previousDir') + ' '
 							+ Zotero.Prefs.get('lastDataDir'),
 						buttonFlags, null,
@@ -332,7 +331,7 @@ var Zotero = new function(){
 					Zotero.getString('startupError.databaseCannotBeOpened'),
 					Zotero.getString('startupError.checkPermissions')
 				]);
-				_startupError = msg;
+				this.startupError = msg;
 			}
 			
 			Components.utils.reportError(e);
@@ -371,10 +370,10 @@ var Zotero = new function(){
 					var kbURL = "http://zotero.org/support/kb/newer_db_version";
 					var seeKB = "See " + kbURL + " for more information.";
 					var msg = Zotero.localeJoin([zoteroVersionIsOlder, upgradeToLatestVersion]) + "\n\n" + currentVersion + "\n\n" + seeKB;
-					_startupError = msg;
+					this.startupError = msg;
 				}
 				else {
-					_startupError = "Database upgrade error";
+					this.startupError = "Database upgrade error";
 				}
 				Components.utils.reportError(e);
 				return false;
diff --git a/chrome/locale/en-US/zotero/zotero.dtd b/chrome/locale/en-US/zotero/zotero.dtd
index a179b5dfb..267ff1771 100644
--- a/chrome/locale/en-US/zotero/zotero.dtd
+++ b/chrome/locale/en-US/zotero/zotero.dtd
@@ -11,6 +11,10 @@
 <!ENTITY zotero.upgrade.newVersionInstalled				"You have installed a new version of Zotero.">
 <!ENTITY zotero.upgrade.upgradeRequired					"Your Zotero database must be upgraded to work with the new version.">
 <!ENTITY zotero.upgrade.autoBackup							"Your existing database will be backed up automatically before any changes are made.">
+<!ENTITY zotero.upgrade.majorUpgrade						"This is a major upgrade.">
+<!ENTITY zotero.upgrade.majorUpgradeBeforeLink				"Be sure you have reviewed the">
+<!ENTITY zotero.upgrade.majorUpgradeLink					"upgrade instructions">
+<!ENTITY zotero.upgrade.majorUpgradeAfterLink				"before continuing.">
 <!ENTITY zotero.upgrade.upgradeInProgress					"Please wait for the upgrade process to finish. This may take a few minutes.">
 <!ENTITY zotero.upgrade.upgradeSucceeded					"Your Zotero database has been successfully upgraded.">
 <!ENTITY zotero.upgrade.changeLogBeforeLink				"Please see">
diff --git a/chrome/locale/en-US/zotero/zotero.properties b/chrome/locale/en-US/zotero/zotero.properties
index 006d7d9c9..a2a08d1d8 100644
--- a/chrome/locale/en-US/zotero/zotero.properties
+++ b/chrome/locale/en-US/zotero/zotero.properties
@@ -31,8 +31,12 @@ install.quickStartGuide.message.welcome 		= Welcome to Zotero!
 install.quickStartGuide.message.clickViewPage	= Click the "View Page" button above to visit our Quick Start Guide and learn how to get started collecting, managing, and citing your research.
 install.quickStartGuide.message.thanks			= Thanks for installing Zotero.
 
+upgrade.failed.title				= Upgrade Failed
 upgrade.failed						= Upgrading of the Zotero database failed:
 upgrade.advanceMessage				= Press %S to upgrade now.
+upgrade.dbUpdateRequired			= The Zotero database must be updated.
+upgrade.integrityCheckFailed		= Your Zotero database must be repaired before the upgrade can continue.
+upgrade.loadDBRepairTool			= Load Database Repair Tool
 
 errorReport.reportErrors			= Report Errors...
 errorReport.reportInstructions		= You can report this error by selecting "%S" from the Actions (gear) menu.
diff --git a/chrome/skin/default/zotero/upgrade.css b/chrome/skin/default/zotero/upgrade.css
index 8ea22a6cf..6b85fdf83 100644
--- a/chrome/skin/default/zotero/upgrade.css
+++ b/chrome/skin/default/zotero/upgrade.css
@@ -2,6 +2,6 @@ description {
 	margin-bottom: 1.5em;
 }
 
-#zotero-change-log-link {
+description > label {
 	margin: 0;
 }