diff --git a/hermes_cli/source_completion.py b/hermes_cli/source_completion.py
index 518f892154..8dbbb0b962 100644
--- a/hermes_cli/source_completion.py
+++ b/hermes_cli/source_completion.py
@@ -60,9 +60,11 @@ def complete_source_checkout(
         completion_message=completion_message,
     )
     if complete:
-        from hermes_cli.source_stamp import write_source_stamp
+        from hermes_cli.source_stamp import refresh_bootstrap_receipt, write_source_stamp
 
-        write_source_stamp(root)
+        stamp = write_source_stamp(root)
+        if stamp is not None:
+            refresh_bootstrap_receipt(root, stamp)
     return complete
 
 
diff --git a/hermes_cli/source_stamp.py b/hermes_cli/source_stamp.py
index b60b51dbe9..c34b6d33db 100644
--- a/hermes_cli/source_stamp.py
+++ b/hermes_cli/source_stamp.py
@@ -60,4 +60,43 @@ def write_source_stamp(root: Path) -> dict | None:
         with suppress(OSError):
             os.unlink(tmp_name)
     _reset_version_info_cache()
-    return stamp
\ No newline at end of file
+    return stamp
+
+
+BOOTSTRAP_RECEIPT = ".hermes-bootstrap-complete"
+
+
+def refresh_bootstrap_receipt(root: Path, stamp: dict) -> None:
+    """Move the installers' bootstrap receipt to the commit ``stamp`` just published.
+
+    install.sh / install.ps1 write the receipt once, at the commit they installed;
+    an update that moves the checkout has to move it too, or it keeps naming the
+    replaced release. Only an existing receipt is refreshed: its presence is what
+    marks a script install, so a manual clone never grows one.
+    """
+    receipt_path = Path(root) / BOOTSTRAP_RECEIPT
+    try:
+        # install.ps1 writes it with Windows PowerShell's UTF-8 BOM.
+        previous = json.loads(receipt_path.read_text(encoding="utf-8-sig"))
+    except FileNotFoundError:
+        return
+    except (OSError, ValueError):
+        previous = {}
+    if not isinstance(previous, dict):
+        previous = {}
+    receipt = {
+        **previous,
+        "schemaVersion": 1,
+        "pinnedCommit": stamp["commit"],
+        # A detached checkout keeps the branch it was installed from.
+        "pinnedBranch": stamp["branch"] or previous.get("pinnedBranch"),
+        "completedAt": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%S.%f")[:-3] + "Z",
+    }
+    fd, tmp_name = tempfile.mkstemp(dir=root, prefix=".hermes-bootstrap-complete.", suffix=".tmp")
+    try:
+        with os.fdopen(fd, "w", encoding="utf-8") as handle:
+            handle.write(json.dumps(receipt, indent=2) + "\n")
+        os.replace(tmp_name, receipt_path)
+    finally:
+        with suppress(OSError):
+            os.unlink(tmp_name)
\ No newline at end of file
diff --git a/tests/hermes_cli/test_source_completion_stamp.py b/tests/hermes_cli/test_source_completion_stamp.py
index ffda7ff0e1..6556ffdd56 100644
--- a/tests/hermes_cli/test_source_completion_stamp.py
+++ b/tests/hermes_cli/test_source_completion_stamp.py
@@ -1,8 +1,10 @@
 """A source checkout publishes identity only after successful completion."""
 
+import json
 import os
 from pathlib import Path
 import subprocess
+import sys
 
 from hermes_cli.source_completion import complete_source_checkout
 
@@ -50,3 +52,37 @@ def test_failed_source_completion_does_not_publish_identity(tmp_path, monkeypatc
 
     assert not complete_source_checkout(root, desktop=False, assume_yes=True)
     assert not (root / "install-stamp.json").exists()
+
+
+def _verify_bootstrap_receipt(root: Path) -> subprocess.CompletedProcess:
+    """The same verifier the Windows install/update E2E runs after an update."""
+    script = Path(__file__).resolve().parents[2] / "scripts" / "verify-bootstrap-version-stamp.py"
+    return subprocess.run([sys.executable, "-B", str(script), "--stamp", str(root / ".hermes-bootstrap-complete"),
+                           "--repo", str(root)], capture_output=True, text=True, encoding="utf-8")
+
+
+def test_update_completion_moves_an_installer_receipt_to_the_updated_head(tmp_path, monkeypatch):
+    root = _repo(tmp_path)
+    release = subprocess.run(["git", "rev-parse", "HEAD"], cwd=root, capture_output=True, text=True, check=True).stdout.strip()
+    branch = subprocess.run(["git", "branch", "--show-current"], cwd=root, capture_output=True, text=True, check=True).stdout.strip()
+    # What install.sh / install.ps1's complete stage leaves behind at the installed release.
+    (root / ".hermes-bootstrap-complete").write_text(json.dumps({
+        "schemaVersion": 1, "pinnedCommit": release, "pinnedBranch": branch, "completedAt": "2026-06-19T00:00:00.000Z",
+    }), encoding="utf-8")
+    subprocess.run(["git", "commit", "-q", "--allow-empty", "-m", "update"], cwd=root, check=True, capture_output=True,
+                   env={**os.environ, "GIT_AUTHOR_NAME": "t", "GIT_AUTHOR_EMAIL": "t@example.invalid",
+                        "GIT_COMMITTER_NAME": "t", "GIT_COMMITTER_EMAIL": "t@example.invalid"})
+    _completion_dependencies(monkeypatch, lambda **_kwargs: True)
+
+    assert complete_source_checkout(root, desktop=False, assume_yes=True)
+    result = _verify_bootstrap_receipt(root)
+    assert result.returncode == 0, result.stdout + result.stderr
+
+
+def test_completion_never_invents_an_installer_receipt(tmp_path, monkeypatch):
+    # The receipt's presence is what marks a script install; a manual clone stays one.
+    root = _repo(tmp_path)
+    _completion_dependencies(monkeypatch, lambda **_kwargs: True)
+
+    assert complete_source_checkout(root, desktop=False, assume_yes=True)
+    assert not (root / ".hermes-bootstrap-complete").exists()