diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32ce78c..deacaad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,21 @@
 
 ## [Unreleased]
 
+## v0.5.9 — hotfix: accept case management kinds in schema validator
+
+### Fixed
+
+- **`talonctl validate` now accepts `CaseNotificationGroup`, `CaseSla`, and
+  `CaseTemplate` envelopes.** The JSON Schema enum in
+  `schemas/envelope.schema.json` was never updated when the three case kinds
+  were added to `KIND_TO_TYPE`, causing `validate_authored_envelope()` to
+  reject all case management templates with an "is not one of" error. The
+  Python code (provider registry, template discovery, `VALID_KINDS`) was
+  correct; only the JSON Schema enum was stale.
+- **Drift-guard test added** (`test_schema_kind_enum_matches_kind_to_type`)
+  that asserts the schema's kind enum exactly matches `KIND_TO_TYPE.keys()`,
+  so the two sources of truth cannot diverge again.
+
 ## v0.5.8 — case management resources (notification groups, SLAs, templates)
 
 ### Added
diff --git a/src/talonctl/schemas/envelope.schema.json b/src/talonctl/schemas/envelope.schema.json
index c857383..2b80991 100644
--- a/src/talonctl/schemas/envelope.schema.json
+++ b/src/talonctl/schemas/envelope.schema.json
@@ -9,7 +9,7 @@
     "apiVersion": { "const": "talon/v2" },
     "kind": {
       "type": "string",
-      "enum": ["Detection", "SavedSearch", "LookupFile", "Workflow", "Dashboard", "RtrScript", "RtrPutFile"]
+      "enum": ["Detection", "SavedSearch", "LookupFile", "Workflow", "Dashboard", "RtrScript", "RtrPutFile", "CaseNotificationGroup", "CaseSla", "CaseTemplate"]
     },
     "metadata": {
       "type": "object",
diff --git a/tests/unit/test_envelope_validation.py b/tests/unit/test_envelope_validation.py
index 923384c..1e516de 100644
--- a/tests/unit/test_envelope_validation.py
+++ b/tests/unit/test_envelope_validation.py
@@ -87,3 +87,28 @@ def test_whitespace_hygiene_checks_metadata_and_nested():
     env = Envelope("talon/v2", "Dashboard", {"resource_id": "d"}, {"widgets": {"w1": {"queryString": "#a\n| b  \n"}}})
     errs = check_whitespace_hygiene(env)
     assert any("trailing whitespace" in e and "widgets.w1.queryString" in e for e in errs)
+
+
+def test_validate_authored_envelope_accepts_case_kinds():
+    """Schema kind enum must include all three case management kinds."""
+    for kind in ("CaseNotificationGroup", "CaseSla", "CaseTemplate"):
+        env = Envelope(
+            "talon/v2",
+            kind,
+            {"resource_id": "test_resource", "name": "Test"},
+            {"name": "Test"},
+        )
+        errors = validate_authored_envelope(env)
+        assert errors == [], f"{kind} rejected by schema: {errors}"
+
+
+def test_schema_kind_enum_matches_kind_to_type():
+    """Schema kind enum must stay in sync with KIND_TO_TYPE (drift guard)."""
+    import json
+    from importlib import resources as importlib_resources
+    from talonctl.core.envelope import KIND_TO_TYPE
+
+    text = importlib_resources.files("talonctl.schemas").joinpath("envelope.schema.json").read_text()
+    schema = json.loads(text)
+    schema_kinds = set(schema["properties"]["kind"]["enum"])
+    assert schema_kinds == set(KIND_TO_TYPE.keys())