diff --git a/scripts/build_courts_list b/scripts/build_courts_list
index 709da5e..0d19583 100755
--- a/scripts/build_courts_list
+++ b/scripts/build_courts_list
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 
 from pathlib import Path
+
 import yaml
 
 print("Loading courts...")
diff --git a/src/ds_caselaw_utils/__init__.py b/src/ds_caselaw_utils/__init__.py
index 8ae00da..f8d9bd7 100644
--- a/src/ds_caselaw_utils/__init__.py
+++ b/src/ds_caselaw_utils/__init__.py
@@ -1,2 +1,4 @@
 from .courts import courts
-from .neutral import neutral_url as neutral_url
+from .neutral import neutral_url
+
+__all__ = ["courts", "neutral_url"]
diff --git a/src/ds_caselaw_utils/neutral.py b/src/ds_caselaw_utils/neutral.py
index 411f653..1899785 100644
--- a/src/ds_caselaw_utils/neutral.py
+++ b/src/ds_caselaw_utils/neutral.py
@@ -4,6 +4,7 @@
 
 import pathlib
 import re
+from typing import Optional
 
 from ruamel.yaml import YAML
 
@@ -13,7 +14,7 @@
     citation_data = yaml.load(f)
 
 
-def neutral_url(citation):
+def neutral_url(citation) -> Optional[str]:
     """Given a neutral citation such as `[2020] EAT 17`,
     return a public-API URL like `/eat/2020/17`, or None
     if no match is found.