diff --git a/src/sdc11073/entity_mdib/entity_consumermdib.py b/src/sdc11073/entity_mdib/entity_consumermdib.py
index c37cd909..4b35319e 100644
--- a/src/sdc11073/entity_mdib/entity_consumermdib.py
+++ b/src/sdc11073/entity_mdib/entity_consumermdib.py
@@ -144,7 +144,7 @@ class EntityConsumerMdib(EntityMdibBase):
 
     def __init__(self,
                  sdc_client: SdcConsumer,
-                 extras_cls: type | None = None,
+                 extras_cls: Callable[[EntityConsumerMdib, loghelper.LoggerAdapter], Any] | None = None,
                  max_realtime_samples: int = 100):
         """Construct a ConsumerMdib instance.