diff --git a/boot/boot.js b/boot/boot.js
index 25101f55e..c54fa53d6 100644
--- a/boot/boot.js
+++ b/boot/boot.js
@@ -795,22 +795,6 @@ $tw.Tiddler.prototype.isDraft = function() {
 	return this.hasField("draft.of");
 };
 
-$tw.Tiddler.prototype.isModified = function() {
-	if(!this.isDraft()) {
-		return false;
-	}
-	var ignoredFields = ["created", "modified", "title", "draft.title", "draft.of", "tags"],
-		tiddler = this,
-		origTiddler = $tw.wiki.getTiddler(this.fields["draft.of"]);
-	if(!$tw.utils.isArrayEqual(tiddler.fields.tags,origTiddler.fields.tags)) {
-		return true;
-	}
-	return !Object.keys(tiddler.fields).every(function(field) {
-		if(ignoredFields.indexOf(field) >= 0) { return true; }
-		return tiddler.fields[field] === origTiddler.fields[field];
-	});
-};
-
 /*
 Register and install the built in tiddler field modules
 */
@@ -1140,6 +1124,22 @@ $tw.Wiki.prototype.deserializeTiddlers = function(type,text,srcFields) {
 	}
 };
 
+$tw.Wiki.prototype.isModifiedTiddler = function(title) {
+  var tiddler = this.getTiddler(title);
+	if(!tiddler.isDraft()) {
+		return false;
+	}
+	var ignoredFields = ["created", "modified", "title", "draft.title", "draft.of", "tags"],
+		origTiddler = this.getTiddler(tiddler.fields["draft.of"]);
+	if(!$tw.utils.isArrayEqual(tiddler.fields.tags,origTiddler.fields.tags)) {
+		return true;
+	}
+	return !Object.keys(tiddler.fields).every(function(field) {
+		if(ignoredFields.indexOf(field) >= 0) { return true; }
+		return tiddler.fields[field] === origTiddler.fields[field];
+	});
+};
+
 /*
 Register the built in tiddler deserializer modules
 */
diff --git a/core/modules/widgets/navigator.js b/core/modules/widgets/navigator.js
index 0f75cb7e9..40aaae9cf 100755
--- a/core/modules/widgets/navigator.js
+++ b/core/modules/widgets/navigator.js
@@ -315,7 +315,7 @@ NavigatorWidget.prototype.handleSaveTiddlerEvent = function(event) {
 						{title: draftTitle}
 					}
 				));
-			} else if(!tiddler.isModified()) {
+			} else if(!this.wiki.isModifiedTiddler(title)) {
 				event.type = "tw-cancel-tiddler";
 				this.dispatchEvent(event);
 			} else if(isConfirmed) {