diff --git a/changelog.d/20250619_165702_jonathan.griffe_fix_gim_backwards_compatibility.md b/changelog.d/20250619_165702_jonathan.griffe_fix_gim_backwards_compatibility.md
new file mode 100644
index 00000000..65258fce
--- /dev/null
+++ b/changelog.d/20250619_165702_jonathan.griffe_fix_gim_backwards_compatibility.md
@@ -0,0 +1,3 @@
+### Changed
+
+- Set PolicyBreak's detector_name and detector_group_name fields as optional to fix backwards compatibility with the GitGuardian API
diff --git a/pygitguardian/models.py b/pygitguardian/models.py
index 0babee2c..4c7df6d7 100644
--- a/pygitguardian/models.py
+++ b/pygitguardian/models.py
@@ -216,8 +216,10 @@ class DiffKind(str, Enum):
 
 class PolicyBreakSchema(BaseSchema):
     break_type = fields.String(data_key="type", required=True)
-    detector_name = fields.String(required=True)
-    detector_group_name = fields.String(required=True)
+    detector_name = fields.String(required=False, load_default=None, dump_default=None)
+    detector_group_name = fields.String(
+        required=False, load_default=None, dump_default=None
+    )
     documentation_url = fields.String(
         required=False, load_default=None, dump_default=None
     )
@@ -251,11 +253,11 @@ class PolicyBreak(FromDictWithBase):
     def __init__(
         self,
         break_type: str,
-        detector_name: str,
-        detector_group_name: str,
         policy: str,
         validity: str,
         matches: List[Match],
+        detector_name: Optional[str] = None,
+        detector_group_name: Optional[str] = None,
         documentation_url: Optional[str] = None,
         known_secret: bool = False,
         incident_url: Optional[str] = None,
diff --git a/tests/test_models.py b/tests/test_models.py
index c46eb5d4..1e068770 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -117,9 +117,6 @@ def test_document_handle_surrogates(self):
                 PolicyBreak,
                 {
                     "type": "hello",
-                    "detector_name": "hello",
-                    "detector_group_name": "hello",
-                    "documentation_url": None,
                     "policy": "hello",
                     "validity": "hey",
                     "matches": [{"match": "hello", "type": "hello"}],