diff --git a/bookwyrm/models/author.py b/bookwyrm/models/author.py
index 5c0c087b2..981e3c0cc 100644
--- a/bookwyrm/models/author.py
+++ b/bookwyrm/models/author.py
@@ -1,5 +1,7 @@
 """ database schema for info about authors """
 import re
+from typing import Tuple, Any
+
 from django.contrib.postgres.indexes import GinIndex
 from django.db import models
 
@@ -38,7 +40,7 @@ class Author(BookDataModel):
     )
     bio = fields.HtmlField(null=True, blank=True)
 
-    def save(self, *args, **kwargs):
+    def save(self, *args: Tuple[Any, ...], **kwargs: dict[str, Any]) -> None:
         """normalize isni format"""
         if self.isni:
             self.isni = re.sub(r"\s", "", self.isni)
diff --git a/bookwyrm/utils/cache.py b/bookwyrm/utils/cache.py
index aebb8e754..5e896e621 100644
--- a/bookwyrm/utils/cache.py
+++ b/bookwyrm/utils/cache.py
@@ -1,8 +1,15 @@
 """ Custom handler for caching """
+from typing import Any, Callable, Tuple, Union
+
 from django.core.cache import cache
 
 
-def get_or_set(cache_key, function, *args, timeout=None):
+def get_or_set(
+    cache_key: str,
+    function: Callable[..., Any],
+    *args: Tuple[Any, ...],
+    timeout: Union[float, None] = None
+) -> Any:
     """Django's built-in get_or_set isn't cutting it"""
     value = cache.get(cache_key)
     if value is None:
diff --git a/bookwyrm/utils/isni.py b/bookwyrm/utils/isni.py
index 318de30ef..6c4200660 100644
--- a/bookwyrm/utils/isni.py
+++ b/bookwyrm/utils/isni.py
@@ -1,15 +1,24 @@
 """ISNI author checking utilities"""
 import xml.etree.ElementTree as ET
+from typing import Union, Optional
+
 import requests
 
 from bookwyrm import activitypub, models
 
 
-def request_isni_data(search_index, search_term, max_records=5):
+def get_element_text(element: Optional[ET.Element]) -> str:
+    """If the element is not None and there is a text attribute return this"""
+    if element is not None and element.text is not None:
+        return element.text
+    return ""
+
+
+def request_isni_data(search_index: str, search_term: str, max_records: int = 5) -> str:
     """Request data from the ISNI API"""
 
     search_string = f'{search_index}="{search_term}"'
-    query_params = {
+    query_params: dict[str, Union[str, int]] = {
         "query": search_string,
         "version": "1.1",
         "operation": "searchRetrieve",
@@ -26,41 +35,52 @@ def request_isni_data(search_index, search_term, max_records=5):
     return result.text
 
 
-def make_name_string(element):
+def make_name_string(element: ET.Element) -> str:
     """create a string of form 'personal_name surname'"""
 
     # NOTE: this will often be incorrect, many naming systems
     # list "surname" before personal name
     forename = element.find(".//forename")
     surname = element.find(".//surname")
-    if forename is not None:
-        return "".join([forename.text, " ", surname.text])
-    return surname.text
+
+    forename_text = get_element_text(forename)
+    surname_text = get_element_text(surname)
+
+    return "".join(
+        [forename_text, " " if forename_text and surname_text else "", surname_text]
+    )
 
 
-def get_other_identifier(element, code):
+def get_other_identifier(element: ET.Element, code: str) -> str:
     """Get other identifiers associated with an author from their ISNI record"""
 
     identifiers = element.findall(".//otherIdentifierOfIdentity")
     for section_head in identifiers:
         if (
-            section_head.find(".//type") is not None
-            and section_head.find(".//type").text == code
-            and section_head.find(".//identifier") is not None
+            (section_type := section_head.find(".//type")) is not None
+            and section_type.text is not None
+            and section_type.text == code
+            and (identifier := section_head.find(".//identifier")) is not None
+            and identifier.text is not None
         ):
-            return section_head.find(".//identifier").text
+            return identifier.text
 
     # if we can't find it in otherIdentifierOfIdentity,
     # try sources
     for source in element.findall(".//sources"):
-        code_of_source = source.find(".//codeOfSource")
-        if code_of_source is not None and code_of_source.text.lower() == code.lower():
-            return source.find(".//sourceIdentifier").text
+        if (
+            (code_of_source := source.find(".//codeOfSource")) is not None
+            and code_of_source.text is not None
+            and code_of_source.text.lower() == code.lower()
+            and (source_identifier := source.find(".//sourceIdentifier")) is not None
+            and source_identifier.text is not None
+        ):
+            return source_identifier.text
 
     return ""
 
 
-def get_external_information_uri(element, match_string):
+def get_external_information_uri(element: ET.Element, match_string: str) -> str:
     """Get URLs associated with an author from their ISNI record"""
 
     sources = element.findall(".//externalInformation")
@@ -69,14 +89,18 @@ def get_external_information_uri(element, match_string):
         uri = source.find(".//URI")
         if (
             uri is not None
+            and uri.text is not None
             and information is not None
+            and information.text is not None
             and information.text.lower() == match_string.lower()
         ):
             return uri.text
     return ""
 
 
-def find_authors_by_name(name_string, description=False):
+def find_authors_by_name(
+    name_string: str, description: bool = False
+) -> list[activitypub.Author]:
     """Query the ISNI database for possible author matches by name"""
 
     payload = request_isni_data("pica.na", name_string)
@@ -92,7 +116,11 @@ def find_authors_by_name(name_string, description=False):
         if not personal_name:
             continue
 
-        author = get_author_from_isni(element.find(".//isniUnformatted").text)
+        author = get_author_from_isni(
+            get_element_text(element.find(".//isniUnformatted"))
+        )
+        if author is None:
+            continue
 
         if bool(description):
 
@@ -111,22 +139,23 @@ def find_authors_by_name(name_string, description=False):
                 # some of the "titles" in ISNI are a little ...iffy
                 # @ is used by ISNI/OCLC to index the starting point ignoring stop words
                 # (e.g. "The @Government of no one")
-                title_elements = [
-                    e
-                    for e in titles
-                    if hasattr(e, "text") and not e.text.replace("@", "").isnumeric()
-                ]
-                if len(title_elements):
-                    author.bio = title_elements[0].text.replace("@", "")
-                else:
-                    author.bio = None
+                author.bio = ""
+                for title in titles:
+                    if (
+                        title is not None
+                        and hasattr(title, "text")
+                        and title.text is not None
+                        and not title.text.replace("@", "").isnumeric()
+                    ):
+                        author.bio = title.text.replace("@", "")
+                        break
 
         possible_authors.append(author)
 
     return possible_authors
 
 
-def get_author_from_isni(isni):
+def get_author_from_isni(isni: str) -> Optional[activitypub.Author]:
     """Find data to populate a new author record from their ISNI"""
 
     payload = request_isni_data("pica.isn", isni)
@@ -135,25 +164,32 @@ def get_author_from_isni(isni):
     # there should only be a single responseRecord
     # but let's use the first one just in case
     element = root.find(".//responseRecord")
-    name = make_name_string(element.find(".//forename/.."))
+    if element is None:
+        # TODO What if there is no responseRecord?
+        #  return empty Author or None, or raise Exception?
+        return None
+
+    name = (
+        make_name_string(forename)
+        if (forename := element.find(".//forename/..")) is not None
+        else ""
+    )
     viaf = get_other_identifier(element, "viaf")
     # use a set to dedupe aliases in ISNI
     aliases = set()
     aliases_element = element.findall(".//personalNameVariant")
     for entry in aliases_element:
         aliases.add(make_name_string(entry))
-    # aliases needs to be list not set
-    aliases = list(aliases)
-    bio = element.find(".//nameTitle")
-    bio = bio.text if bio is not None else ""
+    bio = get_element_text(element.find(".//nameTitle"))
     wikipedia = get_external_information_uri(element, "Wikipedia")
 
     author = activitypub.Author(
-        id=element.find(".//isniURI").text,
+        id=get_element_text(element.find(".//isniURI")),
         name=name,
         isni=isni,
         viafId=viaf,
-        aliases=aliases,
+        # aliases needs to be list not set
+        aliases=list(aliases),
         bio=bio,
         wikipediaLink=wikipedia,
     )
@@ -161,21 +197,27 @@ def get_author_from_isni(isni):
     return author
 
 
-def build_author_from_isni(match_value):
+def build_author_from_isni(match_value: str) -> dict[str, activitypub.Author]:
     """Build basic author class object from ISNI URL"""
 
     # if it is an isni value get the data
     if match_value.startswith("https://isni.org/isni/"):
         isni = match_value.replace("https://isni.org/isni/", "")
-        return {"author": get_author_from_isni(isni)}
+        author = get_author_from_isni(isni)
+        if author is not None:
+            return {"author": author}
     # otherwise it's a name string
     return {}
 
 
-def augment_author_metadata(author, isni):
+def augment_author_metadata(author: models.Author, isni: str) -> None:
     """Update any missing author fields from ISNI data"""
 
     isni_author = get_author_from_isni(isni)
+    if isni_author is None:
+        # TODO Should we just return or raise an exception to indicate a problem?
+        return
+
     isni_author.to_model(model=models.Author, instance=author, overwrite=False)
 
     # we DO want to overwrite aliases because we're adding them to the
diff --git a/bookwyrm/utils/log.py b/bookwyrm/utils/log.py
index 70f32ef03..7a4a2f898 100644
--- a/bookwyrm/utils/log.py
+++ b/bookwyrm/utils/log.py
@@ -10,7 +10,7 @@ class IgnoreVariableDoesNotExist(logging.Filter):
     these errors are not useful to us.
     """
 
-    def filter(self, record):
+    def filter(self, record: logging.LogRecord) -> bool:
         if record.exc_info:
             (_, err_value, _) = record.exc_info
             while err_value:
diff --git a/bookwyrm/utils/validate.py b/bookwyrm/utils/validate.py
index b91add3ad..ed1b00b0e 100644
--- a/bookwyrm/utils/validate.py
+++ b/bookwyrm/utils/validate.py
@@ -1,8 +1,10 @@
 """Validations"""
+from typing import Optional
+
 from bookwyrm.settings import DOMAIN, USE_HTTPS
 
 
-def validate_url_domain(url):
+def validate_url_domain(url: str) -> Optional[str]:
     """Basic check that the URL starts with the instance domain name"""
     if not url:
         return None
diff --git a/mypy.ini b/mypy.ini
index 2a29e314f..f938cc7b6 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -13,6 +13,10 @@ implicit_reexport = True
 [mypy-bookwyrm.connectors.*]
 ignore_errors = False
 
+[mypy-bookwyrm.utils.*]
+ignore_errors = False
+disallow_untyped_calls = False
+
 [mypy-celerywyrm.*]
 ignore_errors = False