diff --git a/messaging/handler.py b/messaging/handler.py
index ed19098..5614927 100644
--- a/messaging/handler.py
+++ b/messaging/handler.py
@@ -422,9 +422,7 @@ class ClaudeMessageHandler:
                         chat_id, status_msg_id, display, parse_mode="MarkdownV2"
                     )
                 except Exception as e:
-                    logger.warning(
-                        f"Failed to update Telegram for node {node_id}: {e}"
-                    )
+                    logger.warning(f"Failed to update Telegram for node {node_id}: {e}")
 
         try:
             try:
diff --git a/tests/test_handler_markdown_and_status_edges.py b/tests/test_handler_markdown_and_status_edges.py
index a2bef8e..ed827e5 100644
--- a/tests/test_handler_markdown_and_status_edges.py
+++ b/tests/test_handler_markdown_and_status_edges.py
@@ -259,7 +259,11 @@ async def test_update_ui_handles_transcript_render_exception():
     session_store = MagicMock()
 
     async def _mock_start_task(*args, **kwargs):
-        yield {"type": "content_block_delta", "index": 0, "delta": {"type": "text_delta", "text": "hi"}}
+        yield {
+            "type": "content_block_delta",
+            "index": 0,
+            "delta": {"type": "text_delta", "text": "hi"},
+        }
         yield {"type": "complete", "status": "success"}
 
     mock_session = MagicMock()
@@ -283,9 +287,7 @@ async def test_update_ui_handles_transcript_render_exception():
     )
     node = MessageNode(node_id="n1", incoming=incoming, status_message_id="s1")
 
-    with patch.object(
-        handler, "_create_transcript_and_render_ctx"
-    ) as mock_create:
+    with patch.object(handler, "_create_transcript_and_render_ctx") as mock_create:
         transcript = MagicMock()
         transcript.render = MagicMock(side_effect=ValueError("render failed"))
         render_ctx = MagicMock()
@@ -361,14 +363,24 @@ async def test_process_parsed_event_malformed_content_continues():
 async def test_handler_update_ui_edit_failure_does_not_crash():
     """When queue_edit_message raises during streaming, _process_node continues and completes."""
     platform = MagicMock()
-    platform.queue_edit_message = AsyncMock(side_effect=RuntimeError("Telegram API error"))
+    platform.queue_edit_message = AsyncMock(
+        side_effect=RuntimeError("Telegram API error")
+    )
     platform.fire_and_forget = MagicMock(
         side_effect=lambda c: getattr(c, "close", lambda: None)()
     )
 
     async def _mock_start_task(*args, **kwargs):
-        yield {"type": "content_block_delta", "index": 0, "delta": {"type": "text_delta", "text": "Hello"}}
-        yield {"type": "content_block_delta", "index": 0, "delta": {"type": "text_delta", "text": " world"}}
+        yield {
+            "type": "content_block_delta",
+            "index": 0,
+            "delta": {"type": "text_delta", "text": "Hello"},
+        }
+        yield {
+            "type": "content_block_delta",
+            "index": 0,
+            "delta": {"type": "text_delta", "text": " world"},
+        }
         yield {"type": "complete", "status": "success"}
 
     mock_session = MagicMock()
diff --git a/tests/test_limiter.py b/tests/test_limiter.py
index bcaa83d..35e6e17 100644
--- a/tests/test_limiter.py
+++ b/tests/test_limiter.py
@@ -252,12 +252,8 @@ class TestMessagingRateLimiter:
         async def fail_task():
             raise RuntimeError("last task failed")
 
-        future1 = asyncio.create_task(
-            limiter.enqueue(ok_task, dedup_key="fail_key")
-        )
-        future2 = asyncio.create_task(
-            limiter.enqueue(fail_task, dedup_key="fail_key")
-        )
+        future1 = asyncio.create_task(limiter.enqueue(ok_task, dedup_key="fail_key"))
+        future2 = asyncio.create_task(limiter.enqueue(fail_task, dedup_key="fail_key"))
 
         with pytest.raises(RuntimeError, match="last task failed"):
             await future1
diff --git a/tests/test_streaming_errors.py b/tests/test_streaming_errors.py
index f93a69f..a48312a 100644
--- a/tests/test_streaming_errors.py
+++ b/tests/test_streaming_errors.py
@@ -509,7 +509,7 @@ class TestStreamChunkEdgeCases:
         tc2 = {
             "index": 0,
             "id": "call_malformed",
-            "function": {"name": None, "arguments": ' never valid }'},
+            "function": {"name": None, "arguments": " never valid }"},
         }
 
         events1 = list(provider._process_tool_call(tc1, sse))
diff --git a/tests/test_transcript.py b/tests/test_transcript.py
index 2475a99..cf6066d 100644
--- a/tests/test_transcript.py
+++ b/tests/test_transcript.py
@@ -145,12 +145,11 @@ def test_transcript_render_segment_exception_skipped():
     t.apply({"type": "text_chunk", "text": "after"})
 
     bad_segment = t._segments[1]
-    original_render = bad_segment.render
 
-    def _raising_render(ctx):
+    def _raising_render(self, ctx):
         raise ValueError("render failed")
 
-    bad_segment.render = _raising_render
+    bad_segment.render = _raising_render  # type: ignore[method-assign]
 
     out = t.render(_ctx(), limit_chars=3900, status=None)
     assert "before" in out