diff --git a/js/serial.js b/js/serial.js
index faff2338..4c3205b5 100644
--- a/js/serial.js
+++ b/js/serial.js
@@ -148,7 +148,7 @@ var serial = {
                     self.bytes_sent += sendInfo.bytesSent;
 
                     // fire callback
-                    callback(sendInfo);
+                    if (callback) callback(sendInfo);
 
                     // remove data for current transmission form the buffer
                     self.output_buffer.shift();
diff --git a/manifest.json b/manifest.json
index 8cb45a4a..f95633d6 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,7 +1,7 @@
 {
     "manifest_version": 2,
     "minimum_chrome_version": "36",
-    "version": "0.54.1",
+    "version": "0.54.2",
 
     "author": "cTn",
     "name": "Baseflight - Configurator",