diff --git a/core/modules/startup/plugins.js b/core/modules/startup/plugins.js
index ab74214b9..fc8ba9589 100644
--- a/core/modules/startup/plugins.js
+++ b/core/modules/startup/plugins.js
@@ -61,7 +61,7 @@ exports.startup = function() {
 				// Collect the shadow tiddlers of any modified plugins
 				$tw.utils.each(changes.modifiedPlugins,function(pluginTitle) {
 					var pluginInfo = $tw.wiki.getPluginInfo(pluginTitle);
-					if(pluginInfo) {
+					if(pluginInfo && pluginInfo.tiddlers) {
 						$tw.utils.each(Object.keys(pluginInfo.tiddlers),function(title) {
 							changedShadowTiddlers[title] = false;
 						});