diff --git a/agent.py b/agent.py
index 99df678..5962b82 100644
--- a/agent.py
+++ b/agent.py
@@ -1012,7 +1012,7 @@ def _validate_one_contract(contract: ContractArtifact) -> ContractCheck:
             Draft202012Validator.check_schema(contract.schema_doc)
             validator = Draft202012Validator(contract.schema_doc)
             for fixture in contract.fixtures:
-                errors = sorted(validator.iter_errors(fixture.payload), key=lambda e: e.path)
+                errors = sorted(validator.iter_errors(fixture.payload), key=_jsonschema_error_path)
                 passed = not errors
                 expected = fixture.should_pass
                 fixture_results.append({"fixture": fixture.name, "passed": passed, "expected": expected, "errors": [e.message for e in errors[:5]]})