diff --git a/bumble/device.py b/bumble/device.py
index 21ca31df..dd0e2490 100644
--- a/bumble/device.py
+++ b/bumble/device.py
@@ -5618,8 +5618,8 @@ def add_default_services(
     async def notify_subscriber(
         self,
         connection: Connection,
-        attribute: Attribute,
-        value: Any | None = None,
+        attribute: Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ) -> None:
         """
@@ -5638,7 +5638,7 @@ async def notify_subscriber(
         await self.gatt_server.notify_subscriber(connection, attribute, value, force)
 
     async def notify_subscribers(
-        self, attribute: Attribute, value: Any | None = None, force: bool = False
+        self, attribute: Attribute[_T], value: _T | None = None, force: bool = False
     ) -> None:
         """
         Send a notification to all the subscribers of an attribute.
@@ -5657,8 +5657,8 @@ async def notify_subscribers(
     async def indicate_subscriber(
         self,
         connection: Connection,
-        attribute: Attribute,
-        value: Any | None = None,
+        attribute: Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ):
         """
@@ -5679,7 +5679,7 @@ async def indicate_subscriber(
         await self.gatt_server.indicate_subscriber(connection, attribute, value, force)
 
     async def indicate_subscribers(
-        self, attribute: Attribute, value: Any | None = None, force: bool = False
+        self, attribute: Attribute[_T], value: _T | None = None, force: bool = False
     ):
         """
         Send an indication to all the subscribers of an attribute.
diff --git a/bumble/gatt_server.py b/bumble/gatt_server.py
index 74be1626..31127fb0 100644
--- a/bumble/gatt_server.py
+++ b/bumble/gatt_server.py
@@ -67,6 +67,8 @@
 # Helpers
 # -----------------------------------------------------------------------------
 
+_T = TypeVar('_T')
+
 
 def _bearer_id(bearer: att.Bearer) -> str:
     if att.is_enhanced_bearer(bearer):
@@ -369,8 +371,8 @@ def send_response(self, bearer: att.Bearer, response: att.ATT_PDU) -> None:
     async def notify_subscriber(
         self,
         bearer: att.Bearer,
-        attribute: att.Attribute,
-        value: bytes | None = None,
+        attribute: att.Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ) -> None:
         if att.is_enhanced_bearer(bearer) or force:
@@ -390,8 +392,8 @@ async def notify_subscriber(
     async def _notify_single_subscriber(
         self,
         bearer: att.Bearer,
-        attribute: att.Attribute,
-        value: bytes | None,
+        attribute: att.Attribute[_T],
+        value: _T | None,
         force: bool,
     ) -> None:
         # Check if there's a subscriber
@@ -411,19 +413,19 @@ async def _notify_single_subscriber(
                 return
 
         # Get or encode the value
-        value = (
+        value_as_bytes = (
             await attribute.read_value(bearer)
             if value is None
             else attribute.encode_value(value)
         )
 
         # Truncate if needed
-        if len(value) > bearer.att_mtu - 3:
-            value = value[: bearer.att_mtu - 3]
+        if len(value_as_bytes) > bearer.att_mtu - 3:
+            value_as_bytes = value_as_bytes[: bearer.att_mtu - 3]
 
         # Notify
         notification = att.ATT_Handle_Value_Notification(
-            attribute_handle=attribute.handle, attribute_value=value
+            attribute_handle=attribute.handle, attribute_value=value_as_bytes
         )
         logger.debug(f'GATT Notify from server: {_bearer_id(bearer)} {notification}')
         self.send_gatt_pdu(bearer, bytes(notification))
@@ -431,8 +433,8 @@ async def _notify_single_subscriber(
     async def indicate_subscriber(
         self,
         bearer: att.Bearer,
-        attribute: att.Attribute,
-        value: bytes | None = None,
+        attribute: att.Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ) -> None:
         if att.is_enhanced_bearer(bearer) or force:
@@ -452,8 +454,8 @@ async def indicate_subscriber(
     async def _indicate_single_bearer(
         self,
         bearer: att.Bearer,
-        attribute: att.Attribute,
-        value: bytes | None,
+        attribute: att.Attribute[_T],
+        value: _T | None,
         force: bool,
     ) -> None:
         # Check if there's a subscriber
@@ -473,19 +475,19 @@ async def _indicate_single_bearer(
                 return
 
         # Get or encode the value
-        value = (
+        value_as_bytes = (
             await attribute.read_value(bearer)
             if value is None
             else attribute.encode_value(value)
         )
 
         # Truncate if needed
-        if len(value) > bearer.att_mtu - 3:
-            value = value[: bearer.att_mtu - 3]
+        if len(value_as_bytes) > bearer.att_mtu - 3:
+            value_as_bytes = value_as_bytes[: bearer.att_mtu - 3]
 
         # Indicate
         indication = att.ATT_Handle_Value_Indication(
-            attribute_handle=attribute.handle, attribute_value=value
+            attribute_handle=attribute.handle, attribute_value=value_as_bytes
         )
         logger.debug(f'GATT Indicate from server: {_bearer_id(bearer)} {indication}')
 
@@ -510,8 +512,8 @@ async def _indicate_single_bearer(
     async def _notify_or_indicate_subscribers(
         self,
         indicate: bool,
-        attribute: att.Attribute,
-        value: bytes | None = None,
+        attribute: att.Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ) -> None:
         # Get all the bearers for which there's at least one subscription
@@ -537,8 +539,8 @@ async def _notify_or_indicate_subscribers(
 
     async def notify_subscribers(
         self,
-        attribute: att.Attribute,
-        value: bytes | None = None,
+        attribute: att.Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ):
         return await self._notify_or_indicate_subscribers(
@@ -547,8 +549,8 @@ async def notify_subscribers(
 
     async def indicate_subscribers(
         self,
-        attribute: att.Attribute,
-        value: bytes | None = None,
+        attribute: att.Attribute[_T],
+        value: _T | None = None,
         force: bool = False,
     ):
         return await self._notify_or_indicate_subscribers(True, attribute, value, force)