diff --git a/ios/listdevices.go b/ios/listdevices.go
index f5fbcb35..604ed01a 100755
--- a/ios/listdevices.go
+++ b/ios/listdevices.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"strings"
+	"time"
 
 	plist "howett.net/plist"
 )
@@ -102,9 +103,47 @@ func (muxConn *UsbMuxConnection) ListDevices() (DeviceList, error) {
 	if err != nil {
 		return DeviceList{}, fmt.Errorf("Failed getting devicelist: %v", err)
 	}
+	muxResponse := MuxResponsefromBytes(response.Payload)
+	if muxResponse.Number == 0xffffffff {
+		// get list of devices from Listen
+		// this is a workaround for the case where connected devices more than 34
+		return muxConn.ListDevicesFromListen()
+	}
 	return DeviceListfromBytes(response.Payload), nil
 }
 
+func (muxConn *UsbMuxConnection) ListDevicesFromListen() (DeviceList, error) {
+	attachedReceiver, err := muxConn.Listen()
+	if err != nil {
+		return DeviceList{}, fmt.Errorf("Failed to start listening: %v", err)
+	}
+	defer muxConn.Close()
+
+	deviceEntryChan := make(chan DeviceEntry)
+	go func() {
+		for {
+			msg, err := attachedReceiver()
+			if err != nil {
+				break
+			}
+			if msg.DeviceAttached() {
+				deviceEntryChan <- msg.DeviceEntry()
+			}
+		}
+	}()
+	var deviceList = DeviceList{
+		DeviceList: make([]DeviceEntry, 0, 40),
+	}
+	for {
+		select {
+		case entry := <-deviceEntryChan:
+			deviceList.DeviceList = append(deviceList.DeviceList, entry)
+		case <-time.After(100 * time.Millisecond):
+			return deviceList, nil
+		}
+	}
+}
+
 // ListDevices returns a DeviceList containing data about all
 // currently connected iOS devices using a new UsbMuxConnection
 func ListDevices() (DeviceList, error) {
diff --git a/ios/mobileactivation/activation.go b/ios/mobileactivation/activation.go
index 14479b62..0af2587e 100644
--- a/ios/mobileactivation/activation.go
+++ b/ios/mobileactivation/activation.go
@@ -1,6 +1,7 @@
 package mobileactivation
 
 import (
+	"fmt"
 	"io"
 	"net/url"
 	"strings"
@@ -77,7 +78,10 @@ func Activate(device ios.DeviceEntry) error {
 		return err
 	}
 	log.Debugf("CreateTunnel1SessionInfoRequest resp: %v", resp)
-	val := resp["Value"].(map[string]interface{})
+	val, ok := resp["Value"].(map[string]interface{})
+	if !ok {
+		return fmt.Errorf("expected 'Value' to be a map, got nil or wrong type")
+	}
 
 	handshakeRequestMessage := val["HandshakeRequestMessage"].([]byte)
 	log.Debugf("HandshakeRequestMessage: %v", handshakeRequestMessage)