diff --git a/.github/workflows/setup.yml b/.github/workflows/setup.yml
index abe182c..3964dc9 100644
--- a/.github/workflows/setup.yml
+++ b/.github/workflows/setup.yml
@@ -89,6 +89,7 @@ jobs:
         path: dist
         merge-multiple: true
     - run: uvx twine check dist/*.whl
+    - run: uvx abi3audit dist/*abi3*.whl
 
   publish:
     if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags/v')
diff --git a/setup.py b/setup.py
index f5557cc..aff0187 100755
--- a/setup.py
+++ b/setup.py
@@ -1,14 +1,28 @@
 #!/usr/bin/env python
 """Setup for the siphashc module."""
 
+import sysconfig
+
 from setuptools import Extension, setup
 
+define_macros = [("Py_LIMITED_API", "0x030A0000")]
+bdist_options = {"py_limited_api": "cp310"}
+
+# Free-threaded Python is not compatible with ABI3, see
+# https://github.com/python/cpython/issues/111506
+if sysconfig.get_config_var("Py_GIL_DISABLED"):
+    define_macros = []
+    bdist_options = {}
+
 setup(
     ext_modules=[
         Extension(
             name="siphashc",
             sources=["siphashc.c", "siphash/siphash.c"],
             language="c",
+            define_macros=define_macros,
+            py_limited_api=True,
         ),
     ],
+    options={"bdist_wheel": bdist_options},
 )