diff --git a/pyproject.toml b/pyproject.toml
index c924cca..ce27432 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,7 +13,7 @@ dependencies = [
 dev = [
     "pre-commit>=4.3.0",
     "pytest>=9.0.1",
-    "ruff>=0.11",
+    "ruff>=0.16,<0.17",
 ]
 
 [tool.ruff]
diff --git a/skills/python-patterns/references/api-clients.md b/skills/python-patterns/references/api-clients.md
index 8b7dd02..2c8c7e6 100644
--- a/skills/python-patterns/references/api-clients.md
+++ b/skills/python-patterns/references/api-clients.md
@@ -15,14 +15,16 @@ LLM outputs often include markdown fences that break JSON parsing. Always clean
 ```python
 import json
 
+
 def clean_llm_response(text):
     for prefix in ("```markdown", "```json", "```"):
         if text.startswith(prefix):
-            text = text[len(prefix):].strip()
+            text = text[len(prefix) :].strip()
     if text.endswith("```"):
         text = text[:-3].strip()
     return text
 
+
 def parse_llm_json(text):
     text = clean_llm_response(text)
     try:
diff --git a/skills/python-patterns/references/testing.md b/skills/python-patterns/references/testing.md
index 353f564..07550ae 100644
--- a/skills/python-patterns/references/testing.md
+++ b/skills/python-patterns/references/testing.md
@@ -10,6 +10,7 @@
 # DataFrame testing
 import pandas.testing as tm
 
+
 def test_feature_engineering():
     input_df = pd.DataFrame({"price": [100, 200], "quantity": [2, 3]})
     result = add_total_column(input_df)