diff --git a/dcicutils/contribution_utils.py b/dcicutils/contribution_utils.py
index ac51a20a3..1b0229610 100644
--- a/dcicutils/contribution_utils.py
+++ b/dcicutils/contribution_utils.py
@@ -4,6 +4,7 @@
 import json
 import os
 import re
+import warnings
 
 from collections import defaultdict
 from dcicutils.diff_utils import DiffManager
@@ -33,10 +34,14 @@ def git_commits(cls, repo_name) -> List[git.Commit]:
         for commit in repo.iter_commits():
             yield cls.json_for_commit(commit)
 
+    @classmethod
+    def author_name(cls, actor: git.Actor) -> str:
+        return actor.name or actor.email.split('@')[0]
+
     @classmethod
     def json_for_actor(cls, actor: git.Actor) -> Dict:
         return {
-            "name": actor.name,
+            "name": cls.author_name(actor),
             "email": actor.email,
         }
 
@@ -55,7 +60,7 @@ class Contributor:
 
     @classmethod
     def create(cls, *, author: git.Actor) -> 'Contributor':
-        return Contributor(email=author.email, name=author.name)
+        return Contributor(email=author.email, name=GitAnalysis.author_name(author))
 
     def __init__(self, *, email: Optional[str] = None, name: Optional[str] = None,
                  emails: Optional[Set[str]] = None, names: Optional[Set[str]] = None,
@@ -480,11 +485,12 @@ def notice_author(*, author: git.Actor, date: datetime.datetime):
                         # PRINT(f"Post-fork contribution from {author.email} ({date})")
                         post_fork_contributors_seen[author.email].append(date)
                 self.notice_reference_time(key=author.email, timestamp=date, timestamps=self.email_timestamps)
-                self.notice_reference_time(key=author.name, timestamp=date, timestamps=self.name_timestamps)
+                self.notice_reference_time(key=GitAnalysis.author_name(author), timestamp=date,
+                                           timestamps=self.name_timestamps)
 
                 contributor_by_email = contributors_by_email.get(author.email)
                 if contributor_by_email:  # already exists, so update it
-                    contributor_by_email.notice_mention_as(email=author.email, name=author.name)
+                    contributor_by_email.notice_mention_as(email=author.email, name=GitAnalysis.author_name(author))
                 else:  # need to create it new
                     contributor_by_email = Contributor.create(author=author)
                     contributors_by_email[author.email] = contributor_by_email
@@ -551,6 +557,7 @@ def traverse(cls,
                              contributors_by_name=contributors_by_name, seen=seen)
         for email in list(cursor.emails):
             contributor = contributors_by_email.get(email)
-            if contributor and contributor not in seen:
+            if contributor and contributor not in seen:  # pragma: no cover - shouldn't happen, included 'just in case'
+                warnings.warn(f"Unexpected stray email seen: {email}")
                 cls.traverse(root=root, cursor=contributor, contributors_by_email=contributors_by_email,
                              contributors_by_name=contributors_by_name, seen=seen)
diff --git a/test/test_contribution_utils.py b/test/test_contribution_utils.py
index 062b97ef1..1095480e6 100644
--- a/test/test_contribution_utils.py
+++ b/test/test_contribution_utils.py
@@ -736,17 +736,27 @@ def test_contributions_init_with_fork_and_no_cache():
 
         mocked_foo_commits: List[Dict] = [
             {
-                "hexsha": "bbbb",
+                "hexsha": "ffff",
+                "committed_datetime": "2020-01-05T12:34:56-05:00",
+                "author": {"name": None, "email": "sal@foo"},
+                "message": "something else"
+            },
+            {
+                "hexsha": "eeee",
+                "committed_datetime": "2020-01-05T12:34:56-05:00",
+                "author": {"name": "Sal", "email": "ssmith@foo"},
+                "message": "something else"
+            },
+            {
+                "hexsha": "dddd",
                 "committed_datetime": "2020-01-04T12:34:56-05:00",
-                "author": {"name": "Sally", "email": "sally.smith@foo"},
-                "co_authors": [{"name": "William Simmons", "email": "bill@someplace"}],
+                "author": {"name": "Sally Smith", "email": "ssmith@foo"},
                 "message": "something else"
             },
             {
-                "hexsha": "bbbb",
+                "hexsha": "cccc",
                 "committed_datetime": "2020-01-03T12:34:56-05:00",
-                "author": {"name": "Sally Smith", "email": "ssmith@foo"},
-                "co_authors": [{"name": "William Simmons", "email": "bill@someplace"}],
+                "author": {"name": "Sally Smith", "email": "sally.smith@foo"},
                 "message": "something else"
             },
             {
@@ -787,12 +797,15 @@ def test_contributions_init_with_fork_and_no_cache():
             }
 
             assert contributions.contributor_values_as_dicts(contributions.contributors_by_email) == {
-                "sally.smith@foo": {"names": ["Sally", "Sally Smith"], "emails": ["sally.smith@foo", "ssmith@foo"]},
-                "ssmith@foo": {"names": ["Sally", "Sally Smith"], "emails": ["sally.smith@foo", "ssmith@foo"]},
+                "sal@foo": {"names": ["sal"], "emails": ["sal@foo"]},
+                "sally.smith@foo": {"names": ["Sal", "Sally", "Sally Smith"],
+                                    "emails": ["sally.smith@foo", "ssmith@foo"]},
+                "ssmith@foo": {"names": ["Sal", "Sally", "Sally Smith"], "emails": ["sally.smith@foo", "ssmith@foo"]},
                 "bill@someplace": {"names": ["William Simmons"], "emails": ["bill@someplace"]},
             }
             assert contributions.contributor_values_as_dicts(contributions.contributors_by_name) == {
-                "Sally Smith": {"names": ["Sally", "Sally Smith"], "emails": ["sally.smith@foo", "ssmith@foo"]},
+                "sal": {"names": ["sal"], "emails": ["sal@foo"]},
+                "Sally Smith": {"names": ["Sal", "Sally", "Sally Smith"], "emails": ["sally.smith@foo", "ssmith@foo"]},
                 "William Simmons": {"names": ["William Simmons"], "emails": ["bill@someplace"]},
             }