diff --git a/shiftregister/messaging/backends/sevenio.py b/shiftregister/messaging/backends/sevenio.py
index 68b6520..e6dc1b4 100644
--- a/shiftregister/messaging/backends/sevenio.py
+++ b/shiftregister/messaging/backends/sevenio.py
@@ -41,7 +41,7 @@ class Receiver(BaseReceiver):
             return
 
         yield Message(
-            data["id"],
+            f"{data['sender']}-{data['time']}",
             recipient=data["system"],
             sender=data["sender"],
             text=data["text"],