diff --git a/pyplumio/const.py b/pyplumio/const.py
index e8ba8edf..afa9f313 100644
--- a/pyplumio/const.py
+++ b/pyplumio/const.py
@@ -47,12 +47,18 @@ class EncryptionType(IntEnum):
     WPA2 = 4
 
 
+EXTRA_STATES: Final = (
+    12,  # STABILIZATION: ecoMAX 810P-L TOUCH
+    23,  # STABILIZATION: ecoMAX 860P3-O
+)
+
+
 @unique
 class DeviceState(IntEnum):
     """Contains device states."""
 
     OFF = 0
-    STABILISATION = 1
+    STABILIZATION = 1
     KINDLING = 2
     WORKING = 3
     SUPERVISION = 4
@@ -64,6 +70,18 @@ class DeviceState(IntEnum):
     UNSEALING = 10
     OTHER = 11
 
+    @classmethod
+    def _missing_(cls, value):
+        """Look up state in extra state table.
+
+        Currently it's only used for stabilisation state,
+        since it differs between models.
+        """
+        if value in EXTRA_STATES:
+            return cls.STABILIZATION
+
+        return None
+
 
 @unique
 class ProductType(IntEnum):
diff --git a/tests/frames/test_messages.py b/tests/frames/test_messages.py
index 2ce83a83..4c651c68 100644
--- a/tests/frames/test_messages.py
+++ b/tests/frames/test_messages.py
@@ -112,10 +112,15 @@ def test_sensor_data_decode_message(messages: dict[FrameType, bytearray]) -> Non
         },
     }
 
-    # Test with the unknown state.
+    # Test with extra state.
     test_message[INDEX_STATE] = 12
     frame = SensorDataMessage(message=test_message)
-    assert frame.data[ATTR_SENSORS][ATTR_STATE] == 12
+    assert frame.data[ATTR_SENSORS][ATTR_STATE] == DeviceState.STABILIZATION
+
+    # Test with the unknown state.
+    test_message[INDEX_STATE] = 99
+    frame = SensorDataMessage(message=test_message)
+    assert frame.data[ATTR_SENSORS][ATTR_STATE] == 99
 
 
 def test_sensor_data_without_fuel_level_and_load(