diff --git a/.github/actions/drift-check/action.yml b/.github/actions/drift-check/action.yml
index dd76c55..ef4e7c6 100644
--- a/.github/actions/drift-check/action.yml
+++ b/.github/actions/drift-check/action.yml
@@ -57,9 +57,9 @@ inputs:
     required: false
     default: '3.11'
   meta-repo-ref:
-    description: 'git ref of TMHSDigital/Developer-Tools-Directory to use for the checker code. Defaults to v1.7 (latest 1.7.x).'
+    description: 'git ref of TMHSDigital/Developer-Tools-Directory to use for the checker code. Defaults to v1 (auto-maintained MAJOR floating tag, per DTD#14). Future MINORs auto-flow through this default without requiring action.yml edits.'
     required: false
-    default: 'v1.7'
+    default: 'v1'
   caller-path:
     description: 'When mode=self, path inside GITHUB_WORKSPACE that points at the caller checkout. Defaults to "." (root).'
     required: false
diff --git a/VERSION b/VERSION
index f8e233b..9ab8337 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.9.0
+1.9.1
diff --git a/tests/test_composite_action_shape.py b/tests/test_composite_action_shape.py
index 31e21e8..2ccec3f 100644
--- a/tests/test_composite_action_shape.py
+++ b/tests/test_composite_action_shape.py
@@ -142,3 +142,27 @@ def test_action_sticky_step_does_not_swallow_rc(action_doc):
     assert "exit \"$RC\"" not in body and "exit $RC" not in body, (
         "sticky step must not propagate its own RC; that's the propagate step's job"
     )
+
+
+def test_meta_repo_ref_default_is_floating_major(action_doc):
+    """The meta-repo-ref input must default to a floating MAJOR tag
+    (v1, v2, ...), never a specific MINOR (v1.7) or PATCH (v1.7.5).
+
+    Regression guard for the bug surfaced during the v1.9.0 ecosystem
+    signal rollout: the default was hardcoded to 'v1.7' and never bumped
+    when 1.8/1.9 shipped. Tool repos consuming the action without an
+    explicit ``meta-repo-ref`` override silently checked out the meta-repo
+    at v1.7, so any tool signals past 1.7.0 produced inverse-direction
+    version-signal warnings.
+
+    Floating-major is the right granularity because DTD#14 auto-maintains
+    v1 to point at the latest 1.x.y release, so future MINORs auto-flow
+    through this default with zero action.yml edits.
+    """
+    import re
+
+    meta_ref_default = action_doc["inputs"]["meta-repo-ref"]["default"]
+    assert re.match(r"^v\d+$", meta_ref_default), (
+        f"meta-repo-ref default must be a floating major tag (v1, v2, ...) "
+        f"per DTD#14 to avoid stale references; got {meta_ref_default!r}"
+    )