diff --git a/changelog.d/20251114_110537_kp2681_scrt_6053_enforce_ignore_reason_for_invalid_state_to_test_credential.md b/changelog.d/20251114_110537_kp2681_scrt_6053_enforce_ignore_reason_for_invalid_state_to_test_credential.md
new file mode 100644
index 00000000..872bece3
--- /dev/null
+++ b/changelog.d/20251114_110537_kp2681_scrt_6053_enforce_ignore_reason_for_invalid_state_to_test_credential.md
@@ -0,0 +1,41 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Removed
+
+- A bullet item for the Removed category.
+
+-->
+<!--
+### Added
+
+- A bullet item for the Added category.
+
+-->
+<!--
+### Changed
+
+- A bullet item for the Changed category.
+
+-->
+<!--
+### Deprecated
+
+- A bullet item for the Deprecated category.
+
+-->
+
+### Fixed
+
+- Added missing "invalid" ignore_reason.
+
+<!--
+### Security
+
+- A bullet item for the Security category.
+
+-->
diff --git a/pygitguardian/models.py b/pygitguardian/models.py
index c33f9ac1..6bfade23 100644
--- a/pygitguardian/models.py
+++ b/pygitguardian/models.py
@@ -917,7 +917,7 @@ class Detector(Base, FromDictMixin):
     "SENSITIVE_FILE",
     "TEST_FILE",
 ]
-IgnoreReason = Literal["test_credential", "false_positive", "low_risk"]
+IgnoreReason = Literal["test_credential", "false_positive", "low_risk", "invalid"]
 OccurrenceKind = Literal["realtime", "historical"]
 OccurrencePresence = Literal["present", "removed"]
 Visibility = Literal["private", "internal", "public"]
diff --git a/tests/test_models.py b/tests/test_models.py
index 12d9d92d..3bc87e93 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -311,7 +311,7 @@ def test_document_handle_surrogates(self):
                         "in_vcs": 3,
                         "removed_in_vcs": 0,
                     },
-                    "ignore_reason": "test_credential",
+                    "ignore_reason": "invalid",
                     "triggered_at": "2019-05-12T09:37:49Z",
                     "ignored_at": "2019-08-24T14:15:22Z",
                     "ignorer_id": 309,