diff --git a/tuf/api/metadata.py b/tuf/api/metadata.py
index 26ad595565..0673011a5c 100644
--- a/tuf/api/metadata.py
+++ b/tuf/api/metadata.py
@@ -177,7 +177,7 @@ def to_file(
             # Use local scope import to avoid circular import errors
             # pylint: disable=import-outside-toplevel
             from tuf.api.serialization.json import JSONSerializer
-            serializer = JSONSerializer(True) # Pass True to compact JSON
+            serializer = JSONSerializer(compact=True)
 
         with tempfile.TemporaryFile() as temp_file:
             temp_file.write(serializer.serialize(self))