diff --git a/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py b/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
index b9d69fd..68ab38b 100644
--- a/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
+++ b/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
@@ -30,7 +30,8 @@
 IDM_CONSUMPTION_FIELD = "LastConsumptionCount"
 NETIDM_CONSUMPTION_FIELD = "LastConsumptionNet"
 SCMPLUS_ID_FIELD = "EndpointID"
-LAST_SEEN_ATTR = "'last_seen': value_json.last_seen"
+LAST_SEEN_ATTR = "last_seen"
+PROTOCOL_ATTR = "Protocol"
 ALL_IDM = [
     "Preamble",
     "PacketLength",
@@ -188,8 +189,6 @@ def create_mqtt_client():
 
 def create_interval_sensor(meter_id, meter, device_name, device_id):
     """Create discovery message for interval consumption sensor."""
-    last_seen_attr = f"{LAST_SEEN_ATTR}," if settings.LAST_SEEN_ENABLED else ""
-
     return set_consumption_details(
         payload={
             "enabled_by_default": True,
@@ -201,7 +200,6 @@ def create_interval_sensor(meter_id, meter, device_name, device_id):
                 "{{ {"
                 f"'{INTERVAL_FIELD}': value_json.{INTERVAL_FIELD},"
                 f"'{INTERVAL_START_FIELD}': value_json.{INTERVAL_START_FIELD},"
-                f"{last_seen_attr}"
                 f"'last_reset': value_json.{INTERVAL_START_FIELD}"
                 "} | tojson }}"
             ),
@@ -242,11 +240,6 @@ def create_sensor(attribute, device_name, device_id, enabled=True, category=None
     if category:
         sensor["entity_category"] = category
 
-    if settings.LAST_SEEN_ENABLED:
-        sensor[
-            "json_attributes_template"
-        ] = f"{{{{ {{ {LAST_SEEN_ATTR} }} | tojson }}}}"
-
     return sensor
 
 
@@ -305,6 +298,22 @@ def send_discovery_messages():
             payload=consumption,
         )
 
+        if settings.LAST_SEEN_ENABLED:
+            last_seen = create_sensor(
+                attribute=LAST_SEEN_ATTR,
+                device_name=device_name,
+                device_id=device_id,
+                enabled=False,
+                category=CATEGORY_DIAGNOSTIC,
+            )
+            last_seen["device_class"] = "timestamp"
+            publish_sensor_discovery(
+                meter_id=meter_id,
+                device=device,
+                attribute=LAST_SEEN_ATTR,
+                payload=last_seen,
+            )
+
         # IDM meters have interval consumption
         if protocol in ["idm", "netidm"]:
             publish_sensor_discovery(
@@ -467,11 +476,11 @@ def main_loop():
                 else:
                     last_seen = math.floor(time.time())
 
-                amr_message["last_seen"] = last_seen
+                amr_message[LAST_SEEN_ATTR] = last_seen
 
             # If in debugging mode, add the protocol to the message
             if settings.WATCHED_PROTOCOLS == "all":
-                amr_message["Protocol"] = msg_type
+                amr_message[PROTOCOL_ATTR] = msg_type
 
             json_message = json.dumps(amr_message)
             logging.debug(