diff --git a/components/zotero-protocol-handler.js b/components/zotero-protocol-handler.js
index 720fdc0c0..a0ce44e08 100644
--- a/components/zotero-protocol-handler.js
+++ b/components/zotero-protocol-handler.js
@@ -895,10 +895,9 @@ function ZoteroProtocolHandler() {
 	var DebugExtension = {
 		loadAsChrome: false,
 		
-		newChannel: function () {
+		newChannel: function (uri) {
 			return new AsyncChannel(uri, function* () {
-				var ioService = Components.classes["@mozilla.org/network/io-service;1"]
-					.getService(Components.interfaces.nsIIOService);
+				this.contentType = "text/plain";
 				
 				try {
 					return Zotero.Debug.get();