diff --git a/bumble/core.py b/bumble/core.py
index f024c12..b4c640c 100644
--- a/bumble/core.py
+++ b/bumble/core.py
@@ -100,6 +100,11 @@ class ConnectionError(BaseError):
     FAILURE            = 0x01
     CONNECTION_REFUSED = 0x02
 
+    def __init__(self, error_code, transport, peer_address, error_namespace='', error_name='', details=''):
+        self.transport = transport
+        self.peer_address = peer_address
+        super().__init__(error_code, error_namespace, error_name, details)
+
 
 # -----------------------------------------------------------------------------
 # UUID
diff --git a/bumble/device.py b/bumble/device.py
index 5393573..67bb3f3 100644
--- a/bumble/device.py
+++ b/bumble/device.py
@@ -1728,12 +1728,11 @@ class Device(CompositeEventEmitter):
         # Notify listeners
         error = ConnectionError(
             error_code,
+            transport,
+            peer_address,
             'hci',
             HCI_Constant.error_name(error_code)
         )
-        error.transport = transport
-        error.connection_handle = connection_handle # FIXME: Connection handle sounds to be a dummy value here
-        error.peer_address = peer_address
         self.emit('connection_failure', error)
 
     @host_event_handler
@@ -1762,6 +1761,8 @@ class Device(CompositeEventEmitter):
         logger.debug(f'*** Disconnection failed: {error_code}')
         error = ConnectionError(
             error_code,
+            connection.transport,
+            connection.peer_address,
             'hci',
             HCI_Constant.error_name(error_code)
         )
diff --git a/bumble/host.py b/bumble/host.py
index 276d334..20a92bf 100644
--- a/bumble/host.py
+++ b/bumble/host.py
@@ -383,7 +383,7 @@ class Host(EventEmitter):
             logger.debug(f'### CONNECTION FAILED: {event.status}')
 
             # Notify the listeners
-            self.emit('connection_failure', BT_LE_TRANSPORT, event.connection_handle, event.peer_address, event.status)
+            self.emit('connection_failure', BT_LE_TRANSPORT, event.peer_address, event.status)
 
     def on_hci_le_enhanced_connection_complete_event(self, event):
         # Just use the same implementation as for the non-enhanced event for now
@@ -413,7 +413,7 @@ class Host(EventEmitter):
             logger.debug(f'### BR/EDR CONNECTION FAILED: {event.status}')
 
             # Notify the client
-            self.emit('connection_failure', BT_BR_EDR_TRANSPORT, event.connection_handle, event.bd_addr, event.status)
+            self.emit('connection_failure', BT_BR_EDR_TRANSPORT, event.bd_addr, event.status)
 
     def on_hci_disconnection_complete_event(self, event):
         # Find the connection
diff --git a/bumble/rfcomm.py b/bumble/rfcomm.py
index be4d406..e47a260 100644
--- a/bumble/rfcomm.py
+++ b/bumble/rfcomm.py
@@ -21,7 +21,7 @@ import asyncio
 from colors import color
 from pyee import EventEmitter
 
-from .core import InvalidStateError, ProtocolError, ConnectionError
+from .core import BT_BR_EDR_TRANSPORT, InvalidStateError, ProtocolError, ConnectionError
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -634,7 +634,12 @@ class Multiplexer(EventEmitter):
         if self.state == Multiplexer.OPENING:
             self.change_state(Multiplexer.CONNECTED)
             if self.open_result:
-                self.open_result.set_exception(ConnectionError(ConnectionError.CONNECTION_REFUSED))
+                self.open_result.set_exception(ConnectionError(
+                    ConnectionError.CONNECTION_REFUSED,
+                    self.l2cap_channel.connection.peer_address,
+                    BT_BR_EDR_TRANSPORT,
+                    'rfcomm'
+                ))
         else:
             logger.warn(f'unexpected state for DM: {self}')