diff --git a/core/core.js b/core/core.js
index d2385e34..0a9344c2 100644
--- a/core/core.js
+++ b/core/core.js
@@ -237,11 +237,13 @@ async function getProcessBlob(blobId, key, options) {
 			process.task.setImports(imports);
 			process.task.activate();
 			let source = await getBlobOrContent(blobId);
+			var appSourceName = blobId;
 			var appSource = utf8Decode(source);
 			try {
 				var app = JSON.parse(appSource);
 				if (app.type == "tildefriends-app") {
-					var id = app.files["app.js"];
+					appSourceName = 'app.js';
+					var id = app.files[appSourceName];
 					var blob = await getBlobOrContent(id);
 					appSource = utf8Decode(blob);
 					await Promise.all(Object.keys(app.files).map(async function(f) {
@@ -256,7 +258,7 @@ async function getProcessBlob(blobId, key, options) {
 			if (process.app) {
 				process.app.send({action: "ready"});
 			}
-			await process.task.execute({name: blobId, source: appSource});
+			await process.task.execute({name: appSourceName, source: appSource});
 		} catch (error) {
 			if (process.app) {
 				process.app.send({action: 'error', error: error});