diff --git a/services/torghut/scripts/run_governance_policy_dry_run.py b/services/torghut/scripts/run_governance_policy_dry_run.py
index a6b0fb17c5..03ea365686 100644
--- a/services/torghut/scripts/run_governance_policy_dry_run.py
+++ b/services/torghut/scripts/run_governance_policy_dry_run.py
@@ -274,7 +274,12 @@ def _int_field_or_default(
     default: int,
 ) -> int:
     value = payload.get(key)
-    return default if value is None else int(value)
+    if value is None or (isinstance(value, str) and not value.strip()):
+        return default
+    try:
+        return int(value)
+    except (OverflowError, TypeError, ValueError):
+        return default
 
 
 def main() -> int:
diff --git a/services/torghut/tests/test_governance_policy_dry_run.py b/services/torghut/tests/test_governance_policy_dry_run.py
index d9b85403d7..5c50575ea2 100644
--- a/services/torghut/tests/test_governance_policy_dry_run.py
+++ b/services/torghut/tests/test_governance_policy_dry_run.py
@@ -336,10 +336,25 @@ def test_dry_run_preserves_zero_expert_router_route_count(self) -> None:
         reasons = output["promotion_prerequisites"]["reasons"]
         self.assertIn("expert_router_registry_route_count_below_minimum", reasons)
 
+    def test_dry_run_defaults_blank_expert_router_route_count(self) -> None:
+        output = self._run_harness(expert_router_route_count="")
+
+        self.assertTrue(output["promotion_progression_allowed"])
+
+    def test_dry_run_defaults_invalid_expert_router_route_count(self) -> None:
+        output = self._run_harness(expert_router_route_count="not-an-integer")
+
+        self.assertTrue(output["promotion_progression_allowed"])
+
+    def test_dry_run_defaults_infinite_expert_router_route_count(self) -> None:
+        output = self._run_harness(expert_router_route_count=float("inf"))
+
+        self.assertTrue(output["promotion_progression_allowed"])
+
     def _run_harness(
         self,
         *extra_args: str,
-        expert_router_route_count: int | None = None,
+        expert_router_route_count: object | None = None,
     ) -> dict[str, object]:
         now = datetime.now(timezone.utc)
         repo_root = Path(__file__).resolve().parents[3]