diff --git a/datasette/app.py b/datasette/app.py
index 1c8577a9e9..6fec250d64 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -335,7 +335,9 @@ def __init__(
             ]
         if config_dir and metadata_files and not metadata:
             with metadata_files[0].open() as fp:
-                metadata = fail_if_plugins_in_metadata(parse_metadata(fp.read()), metadata_files[0].name)
+                metadata = fail_if_plugins_in_metadata(
+                    parse_metadata(fp.read()), metadata_files[0].name
+                )
 
         if config_dir and config_files and not config:
             with config_files[0].open() as fp:
diff --git a/datasette/cli.py b/datasette/cli.py
index e1ea095eae..91f38f698f 100644
--- a/datasette/cli.py
+++ b/datasette/cli.py
@@ -543,7 +543,7 @@ def serve(
 
     metadata_data = None
     if metadata:
-        metadata_data = fail_if_plugins_in_metadata(parse_metadata(metadata.read()), metadata.name)
+        metadata_data = fail_if_plugins_in_metadata(parse_metadata(metadata.read()))
 
     config_data = None
     if config:
diff --git a/datasette/utils/__init__.py b/datasette/utils/__init__.py
index 1b6d5e96cb..0f449b89a1 100644
--- a/datasette/utils/__init__.py
+++ b/datasette/utils/__init__.py
@@ -1269,9 +1269,17 @@ def pairs_to_nested_config(pairs: typing.List[typing.Tuple[str, typing.Any]]) ->
         result = _combine(result, parsed_pair)
     return result
 
-def fail_if_plugins_in_metadata(metadata:dict, filename=None):
-    """ If plugin config is inside metadata, raise an Exception """
+
+def fail_if_plugins_in_metadata(metadata: dict, filename=None):
+    """If plugin config is inside metadata, raise an Exception"""
     if metadata is not None and metadata.get("plugins") is not None:
-        suggested_extension = ".yaml"  if filename is not None and (filename.endswith(".yaml") or filename.endswith(".yml")) else ".json"
-        raise Exception(f'Datasette no longer accepts plugin configuration in --metadata. Move your "plugins" configuration blocks to a separate file - we suggest calling that datasette.{suggested_extension} - and start Datasette with datasette -c datasette.{suggested_extension}. See https://docs.datasette.io/en/latest/configuration.html for more details.')
+        suggested_extension = (
+            ".yaml"
+            if filename is not None
+            and (filename.endswith(".yaml") or filename.endswith(".yml"))
+            else ".json"
+        )
+        raise Exception(
+            f'Datasette no longer accepts plugin configuration in --metadata. Move your "plugins" configuration blocks to a separate file - we suggest calling that datasette.{suggested_extension} - and start Datasette with datasette -c datasette.{suggested_extension}. See https://docs.datasette.io/en/latest/configuration.html for more details.'
+        )
     return metadata