diff --git a/proto/ei-scanner b/proto/ei-scanner
index 76a6444..b10a6ed 100755
--- a/proto/ei-scanner
+++ b/proto/ei-scanner
@@ -140,7 +140,7 @@ class Message:
 
     def add_argument(self, arg: Argument) -> None:
         if arg.name in [a.name for a in self.arguments]:
-                raise ValueError(f"Duplicate argument name '{arg.name}'")
+            raise ValueError(f"Duplicate argument name '{arg.name}'")
         self.arguments.append(arg)
 
     @property
@@ -291,20 +291,19 @@ class Interface:
     mode: str = attr.ib()  # "ei" or "eis"
     description: Optional[Description] = attr.ib(default=None)
 
-
     def add_request(self, request: Request) -> None:
         if request.name in [r.name for r in self.requests]:
-                raise ValueError(f"Duplicate request name '{request.name}'")
+            raise ValueError(f"Duplicate request name '{request.name}'")
         self.requests.append(request)
 
     def add_event(self, event: Event) -> None:
         if event.name in [r.name for r in self.events]:
-                raise ValueError(f"Duplicate event name '{event.name}'")
+            raise ValueError(f"Duplicate event name '{event.name}'")
         self.events.append(event)
 
     def add_enum(self, enum: Enum) -> None:
         if enum.name in [r.name for r in self.enums]:
-                raise ValueError(f"Duplicate enum name '{enum.name}'")
+            raise ValueError(f"Duplicate enum name '{enum.name}'")
         self.enums.append(enum)
 
     @property
@@ -695,7 +694,10 @@ def generate_source(
 
 def main() -> None:
     import textwrap
-    parser = argparse.ArgumentParser(description=textwrap.dedent("""
+
+    parser = argparse.ArgumentParser(
+        description=textwrap.dedent(
+            """
     ei-scanner is a tool to parse the EI protocol description XML and
     pass the data to a Jinja2 template. That template can then be
     used to generate protocol bindings for the desired language.
@@ -726,16 +728,21 @@ def main() -> None:
         {{foo|as_c_arg}} ... resolves to "struct foo *foo"
         {{foo_bar|camel}} ... resolves to "FooBar"
 
-    """),
-    formatter_class=argparse.RawDescriptionHelpFormatter
+    """
+        ),
+        formatter_class=argparse.RawDescriptionHelpFormatter,
     )
 
-    parser.add_argument("--component", type=str, choices=["ei", "eis", "brei"], default="ei")
+    parser.add_argument(
+        "--component", type=str, choices=["ei", "eis", "brei"], default="ei"
+    )
     parser.add_argument(
         "--output", type=str, default="-", help="Output file to write to"
     )
     parser.add_argument("protocol", type=Path, help="The protocol XML file")
-    parser.add_argument("template", type=Path, help="The Jinja2 compatible template file")
+    parser.add_argument(
+        "template", type=Path, help="The Jinja2 compatible template file"
+    )
 
     ns = parser.parse_args()
     assert ns.template.exists()