diff --git a/core/language/en-GB/Misc.multids b/core/language/en-GB/Misc.multids
index e7dfd68c3..35502b737 100644
--- a/core/language/en-GB/Misc.multids
+++ b/core/language/en-GB/Misc.multids
@@ -6,6 +6,7 @@ CloseAll/Button: close all
 ConfirmCancelTiddler: Do you wish to discard changes to the tiddler "<$text text=<<title>>/>"?
 ConfirmDeleteTiddler: Do you wish to delete the tiddler "<$text text=<<title>>/>"?
 ConfirmOverwriteTiddler: Do you wish to overwrite the tiddler "<$text text=<<title>>/>"?
+ConfirmEditShadowTiddler: Your about to edit a ShaddowTiddler. This will override the default system making upgrading non-trivial. Are you sure you want to edit "<$text text=<<title>>/>"?
 InvalidFieldName: Illegal characters in field name "<$text text=<<fieldName>>/>". Fields can only contain lowercase letters and the characters underscore (`_`), hyphen (`-`) and period (`.`)
 MissingTiddler/Hint: Missing tiddler "<$text text=<<currentTiddler>>/>" - click {{$:/core/images/edit-button}} to create
 RecentChanges/DateFormat: DDth MMM YYYY
diff --git a/core/modules/widgets/navigator.js b/core/modules/widgets/navigator.js
index eb0d5425a..0f75cb7e9 100755
--- a/core/modules/widgets/navigator.js
+++ b/core/modules/widgets/navigator.js
@@ -181,9 +181,28 @@ NavigatorWidget.prototype.handleCloseOtherTiddlersEvent = function(event) {
 
 // Place a tiddler in edit mode
 NavigatorWidget.prototype.handleEditTiddlerEvent = function(event) {
+	function isUnmodifiedShadow(title) {
+		// jshint eqnull:true
+		var tiddler = $tw.wiki.getTiddler(title);
+		return (
+			$tw.wiki.isShadowTiddler(title) &&
+			tiddler.fields.modified == null
+		);
+	}
+	function confirmEditShadow(title) {
+		return confirm($tw.language.getString(
+			"ConfirmEditShadowTiddler",
+			{variables:
+				{title: title}
+			}
+		));
+	}
+	var title = event.param || event.tiddlerTitle;
+	if(isUnmodifiedShadow(title) && !confirmEditShadow(title)) {
+		return false;
+	}
 	// Replace the specified tiddler with a draft in edit mode
-	var title = event.param || event.tiddlerTitle,
-		draftTiddler = this.makeDraftTiddler(title),
+	var draftTiddler = this.makeDraftTiddler(title),
 		draftTitle = draftTiddler.fields.title,
 		storyList = this.getStoryList();
 	this.removeTitleFromStory(storyList,draftTitle);