diff --git a/kivyblocks/blocksapp.py b/kivyblocks/blocksapp.py
index 5373caf..e1a0c9c 100644
--- a/kivyblocks/blocksapp.py
+++ b/kivyblocks/blocksapp.py
@@ -123,8 +123,8 @@ class BlocksApp(App):
 			device_id = plyer.uniqueid.id
 		except:
 			pass
-		if isinstance(device,bytes):
-			device_id = device.decode('utf-8')
+		if isinstance(device_id,bytes):
+			device_id = device_id.decode('utf-8')
 
 		d = {
 			'device_id': device_id