diff --git a/.github/workflows/release_publish.yml b/.github/workflows/release_publish.yml
index eee42c028..5c51c69e6 100644
--- a/.github/workflows/release_publish.yml
+++ b/.github/workflows/release_publish.yml
@@ -101,6 +101,17 @@ jobs:
         with:
           ref: ${{ inputs.ref }}
           persist-credentials: false
+      - name: Read the pinned OpenObservation revision
+        id: observation
+        run: |
+          revision=$(bash Scripts/CI/get_revision.sh openobservation)
+          echo "revision=$revision" >> "$GITHUB_OUTPUT"
+      - uses: actions/checkout@v4
+        with:
+          repository: OpenSwiftUIProject/OpenObservation
+          ref: ${{ steps.observation.outputs.revision }}
+          path: observation-repo
+          persist-credentials: false
       - uses: actions/checkout@v4
         with:
           repository: OpenSwiftUIProject/OpenSwiftUI-spm
@@ -112,4 +123,4 @@ jobs:
         env:
           RELEASE_MANIFEST: ${{ needs.assets.outputs.manifest }}
           VERSION: ${{ inputs.version }}
-        run: bash Scripts/CI/update_binary_package.sh "$PWD" "$PWD/binary-repo"
+        run: bash Scripts/CI/update_binary_package.sh "$PWD" "$PWD/binary-repo" "$PWD/observation-repo"
diff --git a/Scripts/CI/Tests/binary-package-tests.js b/Scripts/CI/Tests/binary-package-tests.js
index 24ec95f81..c29202dbc 100644
--- a/Scripts/CI/Tests/binary-package-tests.js
+++ b/Scripts/CI/Tests/binary-package-tests.js
@@ -20,12 +20,15 @@ async function fixture(t) {
   const root = await fs.mkdtemp(path.join(os.tmpdir(), "openswiftui-binary-release-"));
   t.after(() => fs.rm(root, { recursive: true, force: true }));
   const source = path.join(root, "source");
+  const observation = path.join(root, "observation");
   const remote = path.join(root, "remote.git");
   const binary = path.join(root, "binary");
   await fs.mkdir(path.join(source, "Scripts/CI"), { recursive: true });
   await fs.mkdir(path.join(source, "Sources/OpenSwiftUIMacros"), { recursive: true });
   await fs.copyFile(path.join(__dirname, "../release.js"), path.join(source, "Scripts/CI/release.js"));
   await fs.writeFile(path.join(source, "Sources/OpenSwiftUIMacros/Macro.swift"), "// Current macros\n");
+  await fs.mkdir(path.join(observation, "Sources/OpenObservationMacros"), { recursive: true });
+  await fs.writeFile(path.join(observation, "Sources/OpenObservationMacros/Macro.swift"), "// Observation macros\n");
   await fs.mkdir(remote);
   git(remote, "init", "--bare", "--initial-branch=main");
   git(root, "clone", remote, binary);
@@ -41,14 +44,32 @@ async function fixture(t) {
     files: Object.fromEntries(frameworks.map(name => [`${name}.xcframework.zip`, "b".repeat(64)])),
   };
   const run = (overrides = {}) => execFileSync("bash", [
-    path.join(__dirname, "../update_binary_package.sh"), source, binary,
+    path.join(__dirname, "../update_binary_package.sh"), source, binary, observation,
   ], {
     env: { ...gitEnvironment, VERSION: version, RELEASE_MANIFEST: JSON.stringify(manifest), ...overrides },
     encoding: "utf8", stdio: ["ignore", "pipe", "pipe"],
   });
-  return { root, source, remote, binary, manifest, run };
+  return { root, source, observation, remote, binary, manifest, run };
 }
 
+test("binary package publication replaces observation macros and detects mismatched retries", async t => {
+  const { observation, remote, binary, run } = await fixture(t);
+  const macros = "Sources/OpenObservationMacros";
+  await fs.mkdir(path.join(binary, macros), { recursive: true });
+  await fs.writeFile(path.join(binary, macros, "Obsolete.swift"), "// Removed macro\n");
+  git(binary, "add", ".");
+  git(binary, "commit", "-m", "Add an obsolete macro");
+  run();
+  const published = git(remote, "rev-parse", `refs/tags/${version}`);
+  assert.equal(git(remote, "show", `${version}:${macros}/Macro.swift`), "// Observation macros");
+  assert.throws(() => git(remote, "show", `${version}:${macros}/Obsolete.swift`));
+  run();
+  assert.equal(git(remote, "rev-parse", "main"), published);
+  await fs.appendFile(path.join(observation, macros, "Macro.swift"), "// Changed\n");
+  assert.throws(run, /different artifacts or macros/);
+  assert.equal(git(remote, "rev-parse", `refs/tags/${version}`), published);
+});
+
 test("binary package publication creates matching refs and retries without another commit", async t => {
   const { source, remote, binary, run } = await fixture(t);
   run();
diff --git a/Scripts/CI/release.js b/Scripts/CI/release.js
index 0d87de202..c25f7a07a 100644
--- a/Scripts/CI/release.js
+++ b/Scripts/CI/release.js
@@ -177,7 +177,7 @@ async function publishRelease({ github, repo, plan }) {
   }
 }
 
-async function renderBinaryPackage(source, binary, manifest) {
+async function renderBinaryPackage(source, binary, observation, manifest) {
   validateManifest(manifest, manifest.version, manifest.sha);
   const template = await fs.readFile(path.join(binary, "Package.swift.template"), "utf8");
   const values = { VERSION: manifest.version };
@@ -193,9 +193,11 @@ async function renderBinaryPackage(source, binary, manifest) {
     /(\.package\(url:\s*"https:\/\/github\.com\/OpenSwiftUIProject\/OpenSwiftUI-spm",\s*from:\s*")[^"]+("\))/g,
     (_, prefix, suffix) => `${prefix}${manifest.version}${suffix}`,
   ));
-  const macros = path.join(binary, "Sources/OpenSwiftUIMacros");
-  await fs.rm(macros, { recursive: true, force: true });
-  await fs.cp(path.join(source, "Sources/OpenSwiftUIMacros"), macros, { recursive: true });
+  for (const [name, repository] of [["OpenSwiftUIMacros", source], ["OpenObservationMacros", observation]]) {
+    const macros = path.join(binary, "Sources", name);
+    await fs.rm(macros, { recursive: true, force: true });
+    await fs.cp(path.join(repository, "Sources", name), macros, { recursive: true });
+  }
 }
 
 module.exports = {
diff --git a/Scripts/CI/update_binary_package.sh b/Scripts/CI/update_binary_package.sh
index 1f5224696..185cf6cf1 100644
--- a/Scripts/CI/update_binary_package.sh
+++ b/Scripts/CI/update_binary_package.sh
@@ -4,8 +4,10 @@ set -euo pipefail
 
 source_root="$1"
 binary_root="$2"
+observation_root="$3"
 source_root="$(cd "$source_root" && pwd -P)"
 binary_root="$(cd "$binary_root" && pwd -P)"
+observation_root="$(cd "$observation_root" && pwd -P)"
 
 node -e 'require(process.argv[1]).validateVersion(process.env.VERSION)' "$source_root/Scripts/CI/release.js"
 cd "$binary_root"
@@ -18,8 +20,8 @@ if git show-ref --verify --quiet "refs/tags/$VERSION"; then
   git checkout --detach "$VERSION"
 fi
 
-node "$source_root/Scripts/CI/release.js" render-package "$source_root" "$binary_root"
-git add -A -- Package.swift README.md Sources/OpenSwiftUIMacros
+node "$source_root/Scripts/CI/release.js" render-package "$source_root" "$binary_root" "$observation_root"
+git add -A -- Package.swift README.md Sources/OpenSwiftUIMacros Sources/OpenObservationMacros
 
 if [[ "$tag_exists" == true ]]; then
   if ! git diff --cached --quiet; then