diff --git a/bookwyrm/templatetags/status_display.py b/bookwyrm/templatetags/status_display.py
index 96525ca22..430fba198 100644
--- a/bookwyrm/templatetags/status_display.py
+++ b/bookwyrm/templatetags/status_display.py
@@ -1,4 +1,5 @@
 """ template filters """
+import datetime
 from typing import Any, Optional
 from dateutil.relativedelta import relativedelta
 from django import template
@@ -55,7 +56,7 @@ def get_boosted(boost: models.Boost) -> Any:
 
 
 @register.filter(name="published_date")
-def get_published_date(date: str) -> Any:
+def get_published_date(date: datetime.datetime) -> str | None:
     """less verbose combo of humanize filters"""
     if not date:
         return ""
diff --git a/bookwyrm/templatetags/utilities.py b/bookwyrm/templatetags/utilities.py
index 0aabb94f7..f1f7c4bdd 100644
--- a/bookwyrm/templatetags/utilities.py
+++ b/bookwyrm/templatetags/utilities.py
@@ -93,7 +93,7 @@ def get_book_cover_thumbnail(
 
 
 @register.filter(name="get_isni_bio")
-def get_isni_bio(existing: int, author: Author) -> str:
+def get_isni_bio(existing: list[str], author: Author) -> str:
     """Returns the isni bio string if an existing author has an isni listed"""
     auth_isni = re.sub(r"\D", "", str(author.isni))
     if len(existing) == 0: