diff --git a/tuf/api/metadata.py b/tuf/api/metadata.py
index be2f4ddb..0fb91e08 100644
--- a/tuf/api/metadata.py
+++ b/tuf/api/metadata.py
@@ -179,9 +179,9 @@ def to_json_file(
                 The file cannot be written.
 
         """
-        with tempfile.TemporaryFile() as f:
-            f.write(self.to_json(compact).encode('utf-8'))
-            persist_temp_file(f, filename, storage_backend)
+        with tempfile.TemporaryFile() as temp_file:
+            temp_file.write(self.to_json(compact).encode('utf-8'))
+            persist_temp_file(temp_file, filename, storage_backend)
 
 
     # Signatures.