diff --git a/openspec/changes/uv-workspace-packaging/tasks.md b/openspec/changes/uv-workspace-packaging/tasks.md
index cef9833..d830ea5 100644
--- a/openspec/changes/uv-workspace-packaging/tasks.md
+++ b/openspec/changes/uv-workspace-packaging/tasks.md
@@ -5,7 +5,7 @@
   - Baseline: `uv build` -> root sdist and wheel built successfully.
 - [x] 1.2 Add `[tool.uv.workspace]` membership to the root project while retaining `device-agent-runtime` as the root package.
 - [x] 1.3 Create `packages/cloud-platform/pyproject.toml` for the `device-cloud-platform` distribution with explicit build and package-discovery metadata.
-- [ ] 1.4 Declare `device-agent-runtime` as a workspace source dependency of `device-cloud-platform` without adding any reverse dependency.
+- [x] 1.4 Declare `device-agent-runtime` as a workspace source dependency of `device-cloud-platform` without adding any reverse dependency.
 
 ## 2. Cloud Package Extraction
 
diff --git a/packages/cloud-platform/pyproject.toml b/packages/cloud-platform/pyproject.toml
index 2041b1b..15c115a 100644
--- a/packages/cloud-platform/pyproject.toml
+++ b/packages/cloud-platform/pyproject.toml
@@ -3,7 +3,9 @@ name = "device-cloud-platform"
 version = "0.1.0"
 description = "Cloud scheduling, device pooling, plugins, and SDK for Device Agent Runtime."
 requires-python = ">=3.14"
-dependencies = []
+dependencies = [
+    "device-agent-runtime==0.1.0",
+]
 
 [build-system]
 requires = ["setuptools>=69"]
@@ -12,3 +14,6 @@ build-backend = "setuptools.build_meta"
 [tool.setuptools.packages.find]
 where = ["."]
 include = ["cloud*"]
+
+[tool.uv.sources]
+device-agent-runtime = { workspace = true }