diff --git a/core/modules/widgets/jsontiddler.js b/core/modules/widgets/jsontiddler.js
index 571d63f02..d40432e9f 100644
--- a/core/modules/widgets/jsontiddler.js
+++ b/core/modules/widgets/jsontiddler.js
@@ -32,13 +32,7 @@ JSONTiddlerWidget.prototype.render = function(parent,nextSibling) {
 	this.computeAttributes();
 	this.execute();
 	// Collect the fields from the optional base tiddler
-	var fields = {};
-	if(this.attTiddler) {
-		var tiddler = this.wiki.getTiddler(this.attTiddler);
-		if(tiddler) {
-			fields = tiddler.getFieldStrings({exclude: this.attExclude.split(" ")});
-		}
-	}
+	var fields = this.getTiddlerFields();
 	// Add custom fields specified in attributes starting with $
 	$tw.utils.each(this.attributes,function(attribute,name) {
 		if(name.charAt(0) === "$") {
@@ -79,6 +73,17 @@ JSONTiddlerWidget.prototype.refresh = function(changedTiddlers) {
 	}
 };
 
+JSONTiddlerWidget.prototype.getTiddlerFields = function() {
+	var fields = {};
+	if(this.attTiddler) {
+		var tiddler = this.wiki.getTiddler(this.attTiddler);
+		if(tiddler) {
+			fields = tiddler.getFieldStrings({exclude: this.attExclude.split(" ")});
+		}
+	}
+	return fields;
+};
+
 exports.jsontiddler = JSONTiddlerWidget;
 
 })();
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