diff --git a/CHANGELOG.md b/CHANGELOG.md
index c390fc7..97c902c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,18 @@
 
 All notable changes to this project are documented in this file.
 
+## Unreleased
+
+### Fixed
+
+- `create_domain()` no longer fails on every real call. The API answers the
+  `PUT` with a status message (`{"id", "message", "type"}`), not the vhost, and
+  the method tried to parse it as a `Domain`, raising `InvalidResponseError`.
+  The message is now accepted and the returned `Domain` carries the requested
+  name; a message whose `type` is `"error"` raises `InvalidResponseError`
+  instead of being reported as a success. Reported in
+  [issue #9](https://github.com/CleverCloud/clevercloud-sdk-python/issues/9).
+
 ## 0.2.1
 
 Addresses [issue #9](https://github.com/CleverCloud/clevercloud-sdk-python/issues/9),
diff --git a/src/clever_cloud/client.py b/src/clever_cloud/client.py
index c5e9fe2..fba7815 100644
--- a/src/clever_cloud/client.py
+++ b/src/clever_cloud/client.py
@@ -649,9 +649,10 @@ async def create_domain(
                 ignored, so the value round-trips with :attr:`Domain.domain`.
 
         Returns:
-            The domain now attached to the application. This endpoint answers
-            with an empty body on some deployments; the returned value is then
-            built from the requested name.
+            The domain now attached to the application. The API answers with a
+            status message (``{"id", "message", "type"}``) or an empty body
+            rather than the vhost, so the returned value is built from the
+            requested name.
 
         Raises:
             ValueError: If ``domain`` is empty.
@@ -659,6 +660,9 @@ async def create_domain(
                 exist.
             HttpError: If the domain is invalid, or is already attached to
                 another application.
+            InvalidResponseError: If the API answers with a message whose
+                ``type`` is ``"error"`` despite a successful status, or with a
+                body that is neither a message nor a vhost.
         """
         owner = encode_path_segment(owner_id, name="owner_id")
         app = encode_path_segment(app_id, name="app_id")
@@ -671,7 +675,16 @@ async def create_domain(
         )
         if data is None:
             return Domain(domain=fqdn, is_primary=False)
-        return Domain.from_api_response(data)
+        if isinstance(data, dict) and "fqdn" in data:
+            return Domain.from_api_response(data)
+        # The documented answer is a status message, not the vhost.
+        if isinstance(data, dict) and "type" in data:
+            if data["type"] == "error":
+                msg = f"Domain {fqdn!r} was not attached: {data.get('message')!r}"
+                raise InvalidResponseError(msg, response_body=str(data))
+            return Domain(domain=fqdn, is_primary=False)
+        msg = f"Domain: unexpected response to the attach request: {data!r}"
+        raise InvalidResponseError(msg, response_body=str(data))
 
     async def list_domains(self, owner_id: str, app_id: str) -> list[Domain]:
         """List all domains (vhosts) for an application.
diff --git a/tests/test_client.py b/tests/test_client.py
index b765029..b9a6353 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -560,6 +560,43 @@ async def test_create_domain_accepts_an_empty_body(
             )
         assert domain.domain == "app.example.test"
 
+    async def test_create_domain_accepts_a_status_message(
+        self, make_client: Callable[..., CleverCloudClient]
+    ) -> None:
+        """The API answers the PUT with a message, not the vhost (issue #9)."""
+        client = make_client(
+            lambda r: httpx.Response(
+                200, json={"id": 0, "message": "The vhost was added", "type": "success"}
+            )
+        )
+        async with client:
+            domain = await client.create_domain(
+                "orga_1", "app_1", domain="app.example.test/"
+            )
+        assert domain.domain == "app.example.test"
+        assert domain.is_primary is False
+
+    async def test_create_domain_rejects_an_error_message(
+        self, make_client: Callable[..., CleverCloudClient]
+    ) -> None:
+        """An error message must not be reported as an attached domain."""
+        client = make_client(
+            lambda r: httpx.Response(
+                200, json={"id": 0, "message": "vhost refused", "type": "error"}
+            )
+        )
+        async with client:
+            with pytest.raises(InvalidResponseError, match="vhost refused"):
+                await client.create_domain("orga_1", "app_1", domain="app.example.test")
+
+    async def test_create_domain_rejects_an_unknown_body(
+        self, make_client: Callable[..., CleverCloudClient]
+    ) -> None:
+        client = make_client(lambda r: httpx.Response(200, json=["app.example.test"]))
+        async with client:
+            with pytest.raises(InvalidResponseError):
+                await client.create_domain("orga_1", "app_1", domain="app.example.test")
+
     async def test_create_domain_encodes_a_path_suffix(
         self,
         make_client: Callable[..., CleverCloudClient],