diff --git a/bumble/profiles/ascs.py b/bumble/profiles/ascs.py
index ded78973..216874d8 100644
--- a/bumble/profiles/ascs.py
+++ b/bumble/profiles/ascs.py
@@ -452,6 +452,16 @@ class AseStateMachine(gatt.Characteristic):
 
         self.metadata = le_audio.Metadata.from_bytes(metadata)
         self.state = self.State.ENABLING
+        # CIS could be established before enable.
+        if cis_link := next(
+            (
+                cis_link
+                for cis_link in self.service.device.cis_links.values()
+                if cis_link.cig_id == self.cig_id and cis_link.cis_id == self.cis_id
+            ),
+            None,
+        ):
+            self.on_cis_establishment(cis_link)
 
         return (AseResponseCode.SUCCESS, AseReasonCode.NONE)
 
diff --git a/tests/bap_test.py b/tests/bap_test.py
index e8e84f9c..84cf8a1e 100644
--- a/tests/bap_test.py
+++ b/tests/bap_test.py
@@ -16,7 +16,6 @@
 # Imports
 # -----------------------------------------------------------------------------
 import asyncio
-import os
 import functools
 import pytest
 import logging
@@ -55,7 +54,7 @@ from bumble.profiles.pacs import (
     PublishedAudioCapabilitiesServiceProxy,
 )
 from bumble.profiles.le_audio import Metadata
-from tests.test_utils import TwoDevices
+from tests.test_utils import TwoDevices, async_barrier
 
 
 # -----------------------------------------------------------------------------
@@ -441,15 +440,114 @@ async def test_ascs():
     assert (await notifications[1].get())[:2] == bytes([1, AseStateMachine.State.IDLE])
     assert (await notifications[2].get())[:2] == bytes([2, AseStateMachine.State.IDLE])
 
-    await asyncio.sleep(0.001)
+    await async_barrier()
 
 
 # -----------------------------------------------------------------------------
-async def run():
-    await test_pacs()
+@pytest.mark.asyncio
+async def test_ascs_enable_source_then_sink():
+    devices = TwoDevices()
+    ascs_server = AudioStreamControlService(
+        device=devices[1], sink_ase_id=[1], source_ase_id=[2]
+    )
+    sink_ase = ascs_server.ase_state_machines[1]
+    source_ase = ascs_server.ase_state_machines[2]
+    devices[1].add_service(ascs_server)
+    condition = asyncio.Condition()
 
+    async def on_state_change():
+        async with condition:
+            condition.notify_all()
 
-# -----------------------------------------------------------------------------
-if __name__ == '__main__':
-    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
-    asyncio.run(run())
+    sink_ase.on(sink_ase.EVENT_STATE_CHANGE, on_state_change)
+    source_ase.on(sink_ase.EVENT_STATE_CHANGE, on_state_change)
+
+    await devices.setup_connection()
+    peer = device.Peer(devices.connections[0])
+    ascs_client = await peer.discover_service_and_create_proxy(
+        AudioStreamControlServiceProxy
+    )
+
+    # Config Codec
+    config = CodecSpecificConfiguration(
+        sampling_frequency=SamplingFrequency.FREQ_48000,
+        frame_duration=FrameDuration.DURATION_10000_US,
+        audio_channel_allocation=AudioLocation.FRONT_LEFT,
+        octets_per_codec_frame=120,
+        codec_frames_per_sdu=1,
+    )
+    await ascs_client.ase_control_point.write_value(
+        ASE_Config_Codec(
+            ase_id=[1, 2],
+            target_latency=[3, 4],
+            target_phy=[5, 6],
+            codec_id=[CodingFormat(CodecID.LC3), CodingFormat(CodecID.LC3)],
+            codec_specific_configuration=[config, config],
+        )
+    )
+    async with condition:
+        await condition.wait_for(
+            lambda: (
+                sink_ase.state == AseStateMachine.State.CODEC_CONFIGURED
+                and source_ase.state == AseStateMachine.State.CODEC_CONFIGURED
+            )
+        )
+
+    # Config QOS
+    await ascs_client.ase_control_point.write_value(
+        ASE_Config_QOS(
+            ase_id=[1, 2],
+            cig_id=[1, 1],
+            cis_id=[1, 1],
+            sdu_interval=[100, 100],
+            framing=[0, 0],
+            phy=[1, 1],
+            max_sdu=[100, 100],
+            retransmission_number=[16, 16],
+            max_transport_latency=[150, 150],
+            presentation_delay=[10, 10],
+        )
+    )
+    async with condition:
+        await condition.wait_for(
+            lambda: (
+                sink_ase.state == AseStateMachine.State.QOS_CONFIGURED
+                and source_ase.state == AseStateMachine.State.QOS_CONFIGURED
+            )
+        )
+
+    # Enable ASE 2
+    await ascs_client.ase_control_point.write_value(
+        ASE_Enable(ase_id=[2], metadata=[b'foo'])
+    )
+    await async_barrier()
+    cis_handles = await devices[0].setup_cig(
+        device.CigParameters(
+            cig_id=1,
+            cis_parameters=[device.CigParameters.CisParameters(cis_id=1)],
+            sdu_interval_c_to_p=100,
+            sdu_interval_p_to_c=100,
+        )
+    )
+    await devices[0].create_cis([(cis_handles[0], devices.connections[0])])
+
+    async with condition:
+        await condition.wait_for(
+            lambda: (source_ase.state == AseStateMachine.State.ENABLING)
+        )
+    await ascs_client.ase_control_point.write_value(
+        ASE_Receiver_Start_Ready(ase_id=[2])
+    )
+    async with condition:
+        await condition.wait_for(
+            lambda: (source_ase.state == AseStateMachine.State.STREAMING)
+        )
+
+    # Enable ASE 1
+    await ascs_client.ase_control_point.write_value(
+        ASE_Enable(ase_id=[1], metadata=[b'bar'])
+    )
+    async with condition:
+        await condition.wait_for(
+            lambda: (sink_ase.state == AseStateMachine.State.STREAMING)
+        )