diff --git a/tools/github_stats.py b/tools/github_stats.py
index 6a2f8f1..af00a7b 100644
--- a/tools/github_stats.py
+++ b/tools/github_stats.py
@@ -80,7 +80,7 @@ def issues_closed_since(period=timedelta(days=365), project="ipython/ipython", p
     if pulls:
         filtered = [ i for i in filtered if _parse_datetime(i['merged_at']) > since ]
         # filter out PRs not against main (backports)
-        filtered = [ i for i in filtered if i['base']['ref'] == 'main' ]
+        filtered = [i for i in filtered if i["base"]["ref"] == "main"]
     else:
         filtered = [ i for i in filtered if not is_pull_request(i) ]