diff --git a/datasette_publish_vercel/__init__.py b/datasette_publish_vercel/__init__.py
index 31c17c9..7aa18a1 100644
--- a/datasette_publish_vercel/__init__.py
+++ b/datasette_publish_vercel/__init__.py
@@ -214,7 +214,7 @@ def _publish_vercel(
         {
             "name": project,
             "version": 2,
-            "builds": [{"src": "index.py", "use": "@vercel/python"}],
+            "builds": [{"src": "index.py", "use": "@vercel/python@3.0.7"}],
             "routes": [{"src": "(.*)", "dest": "index.py"}],
         },
         indent=4,
diff --git a/tests/test_publish_vercel.py b/tests/test_publish_vercel.py
index d076855..ff216a7 100644
--- a/tests/test_publish_vercel.py
+++ b/tests/test_publish_vercel.py
@@ -312,7 +312,7 @@ def test_generate_vercel_json(mock_run, mock_which):
     assert json.loads(result.output) == {
         "name": "foo",
         "version": 2,
-        "builds": [{"src": "index.py", "use": "@vercel/python"}],
+        "builds": [{"src": "index.py", "use": "@vercel/python@3.0.7"}],
         "routes": [{"src": "(.*)", "dest": "index.py"}],
     }