diff --git a/core/core.js b/core/core.js
index 8a7e8918..fff9e6a9 100644
--- a/core/core.js
+++ b/core/core.js
@@ -540,7 +540,7 @@ function sendData(response, data, type, headers) {
 			response.writeHead(200, Object.assign({"Content-Type": "video/mp4", "Content-Length": data.byteLength}, headers || {}));
 			response.end(data);
 		} else {
-			response.writeHead(200, Object.assign({"Content-Type": type || "text/javascript; charset=utf-8", "Content-Length": data.byteLength}, headers || {}));
+			response.writeHead(200, Object.assign({"Content-Type": type || "application/binary", "Content-Length": data.byteLength}, headers || {}));
 			response.end(data);
 		}
 	} else {
diff --git a/core/index.html b/core/index.html
index 62b86908..43d5236b 100644
--- a/core/index.html
+++ b/core/index.html
@@ -60,7 +60,7 @@
 				</div>
 			</div>
 			<div id="viewPane" class="vbox" style="flex: 1 0; overflow: auto">
-				<iframe id="document" sandbox="allow-forms allow-scripts allow-top-navigation allow-modals" allow="serial" style="width: 100%; height: 100%; border: 0"></iframe>
+				<iframe id="document" sandbox="allow-forms allow-scripts allow-top-navigation allow-modals allow-downloads" style="width: 100%; height: 100%; border: 0"></iframe>
 			</div>
 		</div>
 		<script src="/split/split.min.js"></script>