diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 59278794..ced3eac9 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -36,7 +36,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11", "3.13"]
         platform: [ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v4
diff --git a/Lib/gftools/packager/__init__.py b/Lib/gftools/packager/__init__.py
index e99a144d..8e32a68c 100644
--- a/Lib/gftools/packager/__init__.py
+++ b/Lib/gftools/packager/__init__.py
@@ -423,7 +423,7 @@ def traverse(
         tree = repo.get(tree_oid)
         try:
             entry = tree[subtree_name]
-            existing_subtree = repo.get(entry.hex)
+            existing_subtree = repo.get(entry.id)
             sub_treebuilder = repo.TreeBuilder(existing_subtree)
         except KeyError:
             sub_treebuilder = repo.TreeBuilder()
diff --git a/pyproject.toml b/pyproject.toml
index 4b38a071..998bff06 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,7 +44,9 @@ dependencies = [
   'unidecode',
   'opentype-sanitizer',
   'vttlib',
-  'pygit2<=1.14.1',
+  # pygit2 1.16.0 only supports 3.10+
+  'pygit2==1.15.0; python_version < "3.13"',
+  'pygit2==1.16.0; python_version >= "3.13"',
   'strictyaml',
   'fontmake[json]>=3.3.0',
   'skia-pathops',