diff --git a/CHANGELOG.md b/CHANGELOG.md
index b075ff7..6d7d90e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,21 @@
 
 All notable changes to this project will be documented in this file.
 
+## [0.5.1] - 2026-05-18
+
+### Fixed
+
+- `pull_image` (#3): the 0.5.0 implementation called
+  `SYNO.Docker.Registry/pull_start`, which DSM rejects with
+  "Method does not exist". A live DSM API capture confirmed that
+  `pull_start` actually lives on `SYNO.Docker.Image`, not
+  `SYNO.Docker.Registry`. The Registry API only exposes the
+  synchronous read-only methods (`search`, `tags`, `get/set/create/
+  delete`, `using`). Parameters are unchanged — both `repository`
+  and `tag` are still JSON-encoded — and the `Image/list` polling
+  for completion detection works as before. Note: #3 is already
+  closed; this is the follow-up fix.
+
 ## [0.5.0] - 2026-05-18
 
 ### Added
diff --git a/CLAUDE.md b/CLAUDE.md
index dfce8fb..5d65dcf 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -58,14 +58,19 @@ Only a second consecutive failure is treated as a real auth problem.
   `SYNO.Docker.Project/list` every 2 s for up to 30 s after issuing start.
 - **Image delete** — requires a form-encoded POST with a JSON `images` array
   (confirmed via browser DevTools); uses `DsmClient.post_request()`.
-- **`SYNO.Docker.Image/pull`** — API method exists but behaviour varies by
-  DSM version; not exposed as a standalone tool. `pull_image` uses
-  `SYNO.Docker.Registry/pull_start` instead (see below).
-- **`SYNO.Docker.Registry/pull_start`** — asynchronous pull entry point;
-  no matching `pull_status` method confirmed. `pull_image` polls
-  `SYNO.Docker.Image/list` until `repository:tag` appears (2–10 s backoff,
-  240 s budget) and returns a "still running" hint on timeout instead of
-  raising — DSM keeps pulling server-side regardless of the HTTP response.
+- **`SYNO.Docker.Image/pull` vs. `pull_start`** — the legacy `pull` method
+  exists but behaviour varies by DSM version; not exposed as a standalone
+  tool. `pull_image` uses `SYNO.Docker.Image/pull_start` (asynchronous
+  pull entry point) with both `repository` and `tag` JSON-encoded. Note
+  that `pull_start` lives on **`SYNO.Docker.Image`**, NOT on
+  `SYNO.Docker.Registry` — the Registry API only exposes the synchronous
+  read-only methods (`search`, `tags`, `get/set/create/delete`, `using`);
+  calling `Registry/pull_start` returns "Method does not exist". No
+  matching `pull_status` method is confirmed on either API, so completion
+  is detected by polling `SYNO.Docker.Image/list` until `repository:tag`
+  appears (2–10 s backoff, 240 s budget). Timeout returns a "still
+  running" hint instead of raising — DSM keeps pulling server-side
+  regardless of the HTTP response.
 - **`SYNO.Docker.Registry/tags`** — uses `repo` (JSON-encoded) as the
   parameter name; the n4s4 reference's `name` does not work on this DSM
   version. Returns the tag list as the envelope's `data` field directly,
diff --git a/pyproject.toml b/pyproject.toml
index 1dea638..10d6eac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "mcp-synology-container"
-version = "0.5.0"
+version = "0.5.1"
 description = "MCP server for Synology Container Manager"
 requires-python = ">=3.12"
 dependencies = [
diff --git a/src/mcp_synology_container/modules/registry.py b/src/mcp_synology_container/modules/registry.py
index 4086a2f..1704045 100644
--- a/src/mcp_synology_container/modules/registry.py
+++ b/src/mcp_synology_container/modules/registry.py
@@ -169,9 +169,13 @@ def register_registry(mcp: FastMCP, config: AppConfig, client: DsmClient) -> Non
         if await _image_present(client, repository, tag):
             return f"{target} is already present locally — nothing to pull."
 
+        # `pull_start` lives on SYNO.Docker.Image, NOT SYNO.Docker.Registry
+        # (live DSM capture, confirmed). The Registry API only exposes the
+        # synchronous read-only methods (search, tags, get/set/create/delete,
+        # using).  Calling Registry/pull_start returns "Method does not exist".
         try:
             await client.request(
-                "SYNO.Docker.Registry",
+                "SYNO.Docker.Image",
                 "pull_start",
                 version=1,
                 params={
diff --git a/tests/test_modules/test_registry.py b/tests/test_modules/test_registry.py
index fd0ee54..c24201f 100644
--- a/tests/test_modules/test_registry.py
+++ b/tests/test_modules/test_registry.py
@@ -279,7 +279,7 @@ async def test_pull_image_already_present():
     result = await tools["pull_image"](repository="nginx", tag="1.24", confirmed=True)
     assert "already present" in result
 
-    # Only the Image/list pre-check was called; pull_start must NOT fire.
+    # Only the Image/list pre-check was called; no pull_start of any kind.
     calls = client.request.call_args_list
     assert all(c.args[1] != "pull_start" for c in calls)
 
@@ -307,7 +307,7 @@ async def test_pull_image_confirmed_success(monkeypatch):
                     ]
                 }
             return {"images": []}
-        if api == "SYNO.Docker.Registry" and method == "pull_start":
+        if api == "SYNO.Docker.Image" and method == "pull_start":
             state["pulled"] = True
             return {}
         raise AssertionError(f"Unexpected call: {api}/{method}")
@@ -322,9 +322,11 @@ async def test_pull_image_confirmed_success(monkeypatch):
     assert "Pulled" in result
     assert "nginx:1.24" in result
 
-    # Verify pull_start was invoked with JSON-encoded params
+    # Verify pull_start was invoked on SYNO.Docker.Image (not Registry)
+    # with JSON-encoded params.
     pull_calls = [c for c in client.request.call_args_list if c.args[1] == "pull_start"]
     assert len(pull_calls) == 1
+    assert pull_calls[0].args[0] == "SYNO.Docker.Image"
     params = pull_calls[0].kwargs.get("params", {})
     assert json.loads(params["repository"]) == "nginx"
     assert json.loads(params["tag"]) == "1.24"
@@ -348,7 +350,7 @@ async def test_pull_image_timeout(monkeypatch):
     async def mock_request(api, method, **kwargs):
         if api == "SYNO.Docker.Image" and method == "list":
             return {"images": []}
-        if api == "SYNO.Docker.Registry" and method == "pull_start":
+        if api == "SYNO.Docker.Image" and method == "pull_start":
             return {}
         raise AssertionError(f"Unexpected call: {api}/{method}")
 
@@ -371,7 +373,7 @@ async def test_pull_image_start_error():
     async def mock_request(api, method, **kwargs):
         if api == "SYNO.Docker.Image" and method == "list":
             return {"images": []}
-        if api == "SYNO.Docker.Registry" and method == "pull_start":
+        if api == "SYNO.Docker.Image" and method == "pull_start":
             raise SynologyError("Permission denied", code=105)
         raise AssertionError(f"Unexpected call: {api}/{method}")
 
diff --git a/uv.lock b/uv.lock
index 35a079a..6549658 100644
--- a/uv.lock
+++ b/uv.lock
@@ -362,7 +362,7 @@ wheels = [
 
 [[package]]
 name = "mcp-synology-container"
-version = "0.5.0"
+version = "0.5.1"
 source = { editable = "." }
 dependencies = [
     { name = "click" },