diff --git a/personal_data/fetchers/wanikani_summary.py b/personal_data/fetchers/wanikani_summary.py
index 3583e72..4a39cae 100644
--- a/personal_data/fetchers/wanikani_summary.py
+++ b/personal_data/fetchers/wanikani_summary.py
@@ -1,16 +1,19 @@
 from __future__ import annotations
+
+from collections.abc import Iterator
 from dataclasses import dataclass
 from datetime import datetime, timezone
-from typing import Iterator
+
 import requests
 
 from personal_data.data import DeduplicateMode
 from personal_data.fetchers import Scraper
 from personal_data.secrets import wanikani_api_key
 
+
 @dataclass(frozen=True)
 class WaniKaniSummaryFetcher(Scraper):
-    dataset_name: str = "wanikani_summary"
+    dataset_name: str = 'wanikani_summary'
 
     @staticmethod
     def deduplicate_mode() -> DeduplicateMode:
@@ -19,28 +22,30 @@ class WaniKaniSummaryFetcher(Scraper):
     def scrape(self) -> Iterator[dict]:
         token = wanikani_api_key()
         headers = {
-            "Authorization": f"Bearer {token}",
-            "Wanikani-Revision": "20170710",
+            'Authorization': f'Bearer {token}',
+            'Wanikani-Revision': '20170710',
         }
-        url = "https://api.wanikani.com/v2/summary"
+        url = 'https://api.wanikani.com/v2/summary'
         response = requests.get(url, headers=headers)
         response.raise_for_status()
         data = response.json()
 
-        lessons = data.get("data", {}).get("lessons", [])
-        total_lessons = sum(len(lesson.get("subject_ids", [])) for lesson in lessons)
+        lessons = data.get('data', {}).get('lessons', [])
+        total_lessons = sum(len(lesson.get('subject_ids', [])) for lesson in lessons)
 
-        reviews = data.get("data", {}).get("reviews", [])
+        reviews = data.get('data', {}).get('reviews', [])
         now = datetime.now(timezone.utc)
         total_reviews = 0
         for review in reviews:
-            available_at_str = review.get("available_at")
+            available_at_str = review.get('available_at')
             if available_at_str:
-                available_at = datetime.fromisoformat(available_at_str.replace("Z", "+00:00"))
+                available_at = datetime.fromisoformat(
+                    available_at_str.replace('Z', '+00:00'),
+                )
                 if available_at <= now:
-                    total_reviews += len(review.get("subject_ids", []))
+                    total_reviews += len(review.get('subject_ids', []))
 
         yield {
-            "lessons_available": total_lessons,
-            "reviews_available": total_reviews,
+            'lessons_available': total_lessons,
+            'reviews_available': total_reviews,
         }