diff --git a/mdto/utilities.py b/mdto/utilities.py
index 6ec2fba..b346f09 100644
--- a/mdto/utilities.py
+++ b/mdto/utilities.py
@@ -91,7 +91,9 @@ def _pronominfo_siegfried(file: str | Path) -> BegripGegevens:
     # log sf's warnings (such as extension mismatches)
     warning = match["warning"]
     if warning:
-        helpers.logging.warning(f"siegfried reports PRONOM warning about {file}: {warning}")
+        helpers.logging.warning(
+            f"siegfried reports PRONOM warning about {file}: {warning}"
+        )
 
     return BegripGegevens(
         begripLabel=match["format"],