diff --git a/tests/test_streaming_client.py b/tests/test_streaming_client.py
index a590acd..5df1039 100644
--- a/tests/test_streaming_client.py
+++ b/tests/test_streaming_client.py
@@ -73,6 +73,33 @@ def create_mock_transport(with_init_response=True):
                 except (json.JSONDecodeError, KeyError, AttributeError):
                     pass
 
+            # Keep checking for other control requests (like interrupt)
+            last_check = len(written_messages)
+            timeout_counter = 0
+            while timeout_counter < 100:  # Avoid infinite loop
+                await asyncio.sleep(0.01)
+                timeout_counter += 1
+
+                # Check for new messages
+                for msg_str in written_messages[last_check:]:
+                    try:
+                        msg = json.loads(msg_str.strip())
+                        if msg.get("type") == "control_request":
+                            subtype = msg.get("request", {}).get("subtype")
+                            if subtype == "interrupt":
+                                # Send interrupt response
+                                yield {
+                                    "type": "control_response",
+                                    "response": {
+                                        "request_id": msg.get("request_id"),
+                                        "subtype": "success",
+                                    },
+                                }
+                                return  # End after interrupt
+                    except (json.JSONDecodeError, KeyError, AttributeError):
+                        pass
+                last_check = len(written_messages)
+
         # Then end the stream
         return
 
@@ -326,8 +353,34 @@ class TestClaudeSDKClientStreaming:
                 mock_transport = create_mock_transport()
                 mock_transport_class.return_value = mock_transport
 
-                # Mock the message stream
+                # Mock the message stream with control protocol support
                 async def mock_receive():
+                    # First handle initialization
+                    await asyncio.sleep(0.01)
+                    written = mock_transport.write.call_args_list
+                    for call in written:
+                        data = call[0][0]
+                        try:
+                            msg = json.loads(data.strip())
+                            if (
+                                msg.get("type") == "control_request"
+                                and msg.get("request", {}).get("subtype")
+                                == "initialize"
+                            ):
+                                yield {
+                                    "type": "control_response",
+                                    "response": {
+                                        "request_id": msg.get("request_id"),
+                                        "subtype": "success",
+                                        "commands": [],
+                                        "output_style": "default",
+                                    },
+                                }
+                                break
+                        except (json.JSONDecodeError, KeyError, AttributeError):
+                            pass
+
+                    # Then yield the actual messages
                     yield {
                         "type": "assistant",
                         "message": {
@@ -383,8 +436,24 @@ class TestClaudeSDKClientStreaming:
                 mock_transport_class.return_value = mock_transport
 
                 async with ClaudeSDKClient() as client:
+                    # Interrupt is now handled via control protocol
                     await client.interrupt()
-                    mock_transport.interrupt.assert_called_once()
+                    # Check that a control request was sent via write
+                    write_calls = mock_transport.write.call_args_list
+                    interrupt_found = False
+                    for call in write_calls:
+                        data = call[0][0]
+                        try:
+                            msg = json.loads(data.strip())
+                            if (
+                                msg.get("type") == "control_request"
+                                and msg.get("request", {}).get("subtype") == "interrupt"
+                            ):
+                                interrupt_found = True
+                                break
+                        except (json.JSONDecodeError, KeyError, AttributeError):
+                            pass
+                    assert interrupt_found, "Interrupt control request not found"
 
         anyio.run(_test)