diff --git a/lib/utility.js b/lib/utility.js
index bd73344..8b52ee7 100644
--- a/lib/utility.js
+++ b/lib/utility.js
@@ -33,7 +33,8 @@ function callService(service, emitter, channel, callback) {
     return new Promise(function (fulfill, reject) {
         emitter.once('error', reject);
         emitter.once(eventName, function (result) {
-            if ('mtproto.type.Rpc_error' == result.typeName) {
+            emitter.removeListener('error', reject);
+            if (result.instanceOf('mtproto.type.Rpc_error')) {
                 reject(new Error(result.error_message));
             } else {
                 fulfill(result);
diff --git a/package.json b/package.json
index 36b142a..0e200d4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "telegram.link",
-  "version": "0.6.0",
+  "version": "0.6.1",
   "description": "Telegram API library",
   "keywords": [
     "telegram",