diff --git a/src/io/bleSession.js b/src/io/bleSession.js
index 983399c90..600373ea3 100644
--- a/src/io/bleSession.js
+++ b/src/io/bleSession.js
@@ -138,8 +138,7 @@ class BLESession extends JSONRPCWebSocket {
 
     _sendError (e) {
         this._connected = false;
-        log.error(`BLESession error:`);
-        log.error(e);
+        log.error(`BLESession error: ${e}`);
         this._runtime.emit(this._runtime.constructor.PERIPHERAL_ERROR);
     }
 }
diff --git a/src/io/btSession.js b/src/io/btSession.js
index 7d1f6a4c8..d0dfea3c7 100644
--- a/src/io/btSession.js
+++ b/src/io/btSession.js
@@ -10,6 +10,7 @@ class BTSession extends JSONRPCWebSocket {
      * @param {Runtime} runtime - the Runtime for sending/receiving GUI update events.
      * @param {object} deviceOptions - the list of options for device discovery.
      * @param {object} connectCallback - a callback for connection.
+     * @param {object} messageCallback - a callback for message sending.
      */
     constructor (runtime, deviceOptions, connectCallback, messageCallback) {
         const ws = new WebSocket(ScratchLinkWebSocket);
@@ -107,8 +108,7 @@ class BTSession extends JSONRPCWebSocket {
     }
 
     _sendError (e) {
-        log.error(`BLESession error:`);
-        log.error(e);
+        log.error(`BLESession error: ${e}`);
         this._runtime.emit(this._runtime.constructor.PERIPHERAL_ERROR);
     }
 }
diff --git a/src/util/jsonrpc-web-socket.js b/src/util/jsonrpc-web-socket.js
index 39b60b92b..c06a269b5 100644
--- a/src/util/jsonrpc-web-socket.js
+++ b/src/util/jsonrpc-web-socket.js
@@ -1,4 +1,5 @@
 const JSONRPC = require('./jsonrpc');
+const log = require('../util/log');
 
 class JSONRPCWebSocket extends JSONRPC {
     constructor (webSocket) {
@@ -28,7 +29,7 @@ class JSONRPCWebSocket extends JSONRPC {
     _onSocketMessage (e) {
         const json = JSON.parse(e.data);
         if (json.method !== 'characteristicDidChange') {
-            console.log('received message: ' + JSON.stringify(json));
+            // log.info(`received message: ${json}`);
         }
         this._handleMessage(json);
     }