diff --git a/other-test-repos/tag-test.py b/other-test-repos/tag-test.py
new file mode 100755
index 00000000..f66e393
--- /dev/null
+++ b/other-test-repos/tag-test.py
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+
+import datetime
+import subprocess
+import time
+import sys
+
+import util
+
+email = b'a@a.com'
+name = b''
+
+util.init()
+tree = util.create_tree_with_one_file()
+commit, _, _ = util.save_commit_object(
+    tree,
+    (None,),
+    author_date_s=0,
+    author_email=email,
+    author_name=name,
+    committer_date_s=0,
+    committer_email=email,
+    committer_name=name,
+    message=b'',
+)
+tag_sha, _, _ = util.save_tag_object(
+    commit,
+    b'mytag',
+    object_type=b'commit',
+    user_name=name,
+    user_email=email,
+    date_s=0,
+    message=b'abc'
+)
+util.create_master(commit)
diff --git a/other-test-repos/util.py b/other-test-repos/util.py
index 82ae60a..8b9593e 100644
--- a/other-test-repos/util.py
+++ b/other-test-repos/util.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 """
 TODO packfile operations instead of just object. Could be more efficient.
 But also harder to implement that format.
@@ -12,6 +14,8 @@
 repo_dir = 'repo.tmp'
 git_dir = b'.git'
 objects_dir = os.path.join(git_dir, b'objects')
+refs_dir = os.path.join(git_dir, b'refs')
+tags_dir = os.path.join(refs_dir, b'tags')
 
 # Tree parameters.
 default_blob_basename = b'a'
@@ -87,6 +91,23 @@ def save_commit_object(
             message)
     return save_object(b'commit', commit_content) + (commit_content,)
 
+def save_tag_object(
+        object_sha_ascii,
+        tag_name,
+        object_type='commit',
+        user_name=default_author_name,
+        user_email=default_author_email,
+        date_s=default_author_date_s,
+        date_tz=default_author_date_tz,
+        message=default_message):
+    content = b'object %s\ntype %s\ntag %s\ntagger %s <%s> %s %s\n\n%s' % \
+      (object_sha_ascii, object_type, tag_name, user_name, user_email, str(date_s).encode('ascii'), date_tz, message)
+    tag_sha_ascii, tag_sha = save_object(b'tag', content)
+    os.makedirs(tags_dir, exist_ok=True)
+    with open(os.path.join(tags_dir, tag_name), 'w') as tag_file:
+        tag_file.write(tag_sha_ascii.decode('ascii') + '\n')
+    return tag_sha_ascii, tag_sha, content
+
 def get_git_hash_object(obj_type, input):
     cmd = [b'git', b'hash-object', b'--stdin', b'-t', obj_type]
     return subprocess.check_output(cmd, input=input).rstrip()