diff --git a/src/extensions/scratch3_wedo2/index.js b/src/extensions/scratch3_wedo2/index.js
index 0fc01e2c304..a158269e5fc 100644
--- a/src/extensions/scratch3_wedo2/index.js
+++ b/src/extensions/scratch3_wedo2/index.js
@@ -460,9 +460,8 @@ class WeDo2 {
     // TODO: rename scan?
     startDeviceScan () {
         this._ble = new BLESession(this._runtime, {
-            filters: [
-                {services: [UUID.DEVICE_SERVICE, UUID.IO_SERVICE]}
-            ]
+            filters: [{services: [UUID.DEVICE_SERVICE]}],
+            optionalServices: [UUID.IO_SERVICE]
         }, this._onConnect);
     }
 
@@ -517,6 +516,10 @@ class WeDo2 {
             })
             .then(() => {
                 // register for attached io notifications
+                // TODO: make backwards compatible with 'read':
+                // - try 'startNotifications'
+                // - then try 'read' with 'startNotifications' flag
+                // - then catch OSX and Windows errors
                 this._ble.startNotifications(UUID.DEVICE_SERVICE, UUID.ATTACHED_IO, this._onMessage);
             });
     }
@@ -626,6 +629,10 @@ class WeDo2 {
 
             this._send(UUID.INPUT_COMMAND, Base64Util.uint8ArrayToBase64(cmd))
                 .then(() => {
+                    // TODO: make backwards compatible with 'read':
+                    // - try 'startNotifications'
+                    // - then try 'read' with 'startNotifications' flag
+                    // - then catch OSX and Windows errors
                     this._ble.startNotifications(UUID.IO_SERVICE, UUID.INPUT_VALUES, this._onMessage);
                 });
         }
diff --git a/src/io/bleSession.js b/src/io/bleSession.js
index d2d053121a9..b44c314f70f 100644
--- a/src/io/bleSession.js
+++ b/src/io/bleSession.js
@@ -1,5 +1,5 @@
 const JSONRPCWebSocket = require('../util/jsonrpc-web-socket');
-const log = require('../util/log');
+// const log = require('../util/log');
 const ScratchLinkWebSocket = 'wss://device-manager.scratch.mit.edu:20110/scratch/ble';
 
 class BLESession extends JSONRPCWebSocket {
@@ -115,17 +115,7 @@ class BLESession extends JSONRPCWebSocket {
             characteristicId
         };
         this._characteristicDidChangeCallback = onCharacteristicChanged;
-        return this.sendRemoteRequest('startNotifications', params)
-            .catch(() => {
-                // backwards compatibility: try read
-                this.read(serviceId, characteristicId, true, onCharacteristicChanged)
-                    .catch(e => {
-                        // if read not allowed, send error
-                        if (e.data !== 'Reading is not permitted.') { // OSX error TODO: Windows error?
-                            this._sendError(e);
-                        }
-                    });
-            });
+        return this.sendRemoteRequest('startNotifications', params);
     }
 
     /**
@@ -145,7 +135,12 @@ class BLESession extends JSONRPCWebSocket {
             params.startNotifications = true;
         }
         this._characteristicDidChangeCallback = onCharacteristicChanged;
-        return this.sendRemoteRequest('read', params);
+        return this.sendRemoteRequest('read', params)
+            .catch(e => {
+                if (e.data !== 'Reading is not permitted.') { // TODO: move this error check to extension
+                    this._sendError(e);
+                }
+            });
     }
 
     /**
@@ -171,9 +166,9 @@ class BLESession extends JSONRPCWebSocket {
             });
     }
 
-    _sendError (e) {
+    _sendError (/* e */) {
         this._connected = false;
-        log.error(`BLESession error: ${JSON.stringify(e)}`);
+        // log.error(`BLESession error: ${JSON.stringify(e)}`);
         this._runtime.emit(this._runtime.constructor.PERIPHERAL_ERROR);
     }