diff --git a/test/serena/test_file_tools.py b/test/serena/test_file_tools.py
index a2e056e2..24c1649d 100644
--- a/test/serena/test_file_tools.py
+++ b/test/serena/test_file_tools.py
@@ -17,7 +17,7 @@ def read_file_tool(tmp_path: Path) -> ReadFileTool:
     agent.get_active_project_or_raise.return_value = project
     tool = ReadFileTool(agent)
     # bypass the length limit, which would otherwise depend on the agent configuration
-    tool._limit_length = lambda result, max_answer_chars: result  # type: ignore[method-assign]
+    tool._limit_length = lambda result, max_answer_chars: result
     return tool