diff --git a/src/simdb/remote/apis/__init__.py b/src/simdb/remote/apis/__init__.py
index b75a9680..2f8a7803 100644
--- a/src/simdb/remote/apis/__init__.py
+++ b/src/simdb/remote/apis/__init__.py
@@ -36,6 +36,26 @@ def register(api, version, namespaces):
     version_str = version.replace(".", "_")
     blueprint = Blueprint(f"api_{version_str}", f"{__name__}.{version_str}")
     blueprints[version] = blueprint
+
+    def index():
+        return jsonify(
+            {
+                "api": "simdb",
+                "api_version": api.version,
+                "server_version": __version__,
+                "endpoints": [
+                    request.url + "simulations",
+                    request.url + "files",
+                    request.url + "validation_schema",
+                    request.url + "metadata",
+                    request.url + "upload_options",
+                ],
+                "documentation": request.url + "docs",
+            }
+        )
+
+    api.render_root = index
+
     api.init_app(blueprint)
 
     for namespace in namespaces:
@@ -78,21 +98,7 @@ def handle_authentication_error(err: Exception):
     class Index(Resource):
         @api.doc(security=[])
         def get(self):
-            return jsonify(
-                {
-                    "api": "simdb",
-                    "api_version": api.version,
-                    "server_version": __version__,
-                    "endpoints": [
-                        request.url + "simulations",
-                        request.url + "files",
-                        request.url + "validation_schema",
-                        request.url + "metadata",
-                        request.url + "upload_options",
-                    ],
-                    "documentation": request.url + "docs",
-                }
-            )
+            return index()
 
     @api.route("/token")
     class Token(Resource):
diff --git a/tests/remote/api/test_index.py b/tests/remote/api/test_index.py
new file mode 100644
index 00000000..608fadcc
--- /dev/null
+++ b/tests/remote/api/test_index.py
@@ -0,0 +1,16 @@
+import pytest
+
+from simdb.remote.apis import blueprints
+
+
+@pytest.mark.parametrize("version", list(blueprints))
+def test_versioned_index(client, version):
+    """The versioned root must serve the index JSON, not flask-restx's 404 root."""
+    rv = client.get(f"/{version}/")
+
+    assert rv.status_code == 200
+    assert rv.json["api"] == "simdb"
+    # v1 reports "1.0" for blueprint key "v1", so only compare the prefix
+    assert rv.json["api_version"].startswith(version.lstrip("v"))
+    assert "server_version" in rv.json
+    assert any(url.endswith("simulations") for url in rv.json["endpoints"])