diff --git a/.python-version b/.python-version
index bd28b9c..2c07333 100644
--- a/.python-version
+++ b/.python-version
@@ -1 +1 @@
-3.9
+3.11
diff --git a/pyproject.toml b/pyproject.toml
index d9e9c20..e0f22c6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ name = "mediawiki-dump-tools"
 version = "0.1.1"
 description = "Add your description here"
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.11"
 dependencies = [
     "deltas>=0.7.0",
     "mediawiki-utilities>=0.4.18",
@@ -16,6 +16,10 @@ dependencies = [
     "pyarrow>=20.0.0",
     "pywikidiff2 @ git+https://gitea.communitydata.science/groceryheist/pywikidiff2.git",
     "sortedcontainers>=2.4.0",
+    # PyPI yamlconf 0.2.6 pins pyyaml == 5.4.1, which cannot build on
+    # Python >= 3.11; this fork loosens the pin. Drop once upstream
+    # releases with a fixed requirement.
+    "yamlconf @ git+https://github.com/groceryheist/yamlconf",
 ]
 
 [project.scripts]