diff --git a/core/fixtures/retention_release_oracle.json b/core/fixtures/retention_release_oracle.json
index 0f4ecad67..a48d9fc6a 100644
--- a/core/fixtures/retention_release_oracle.json
+++ b/core/fixtures/retention_release_oracle.json
@@ -2,7 +2,7 @@
   "_provenance": {
     "generator": "scripts/retention_release_oracle.py",
     "method": "the reference verdicts are OBSERVED by running the reference over constructed segments on a real filesystem; the unified verdicts are derived mechanically from one rule, not chosen per row",
-    "source_revision": "ba31b082b8588298a229df8d925cb42c1825a09d",
+    "source_revision": "6a3b35b269cd8fd5d1aea8d40ff63d1d215d0ad0",
     "reference": {
       "segment_gate": "solstone/think/retention.py:190",
       "state_derivation": "solstone/think/data_state.py:121",
diff --git a/scripts/retention_release_oracle.py b/scripts/retention_release_oracle.py
index 987599076..b43420f22 100644
--- a/scripts/retention_release_oracle.py
+++ b/scripts/retention_release_oracle.py
@@ -482,9 +482,19 @@ def tally(rows: list[dict]) -> dict[str, int]:
 
 
 def revision() -> str:
+    """The revision of the reference this oracle was read from.
+
+    ⛔ Deliberately NOT ``rev-parse HEAD``. Pinning HEAD makes the committed
+    fixture stale on every unrelated commit in the repository, so the gate reds
+    for a reason that has nothing to do with the reference it guards -- which
+    means the gate is the defect. Pinning the last commit that touched the
+    reference files goes stale exactly when the fixture should be regenerated,
+    and not otherwise.
+    """
+    sources = sorted({citation.split(":", 1)[0] for citation in REFERENCE.values()})
     try:
         return subprocess.run(
-            ["git", "rev-parse", "HEAD"],
+            ["git", "log", "-1", "--format=%H", "--", *sources],
             cwd=REPO,
             capture_output=True,
             text=True,