diff --git a/litellm/router.py b/litellm/router.py
index fac48b45fb3..5ee57272326 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -9520,8 +9520,10 @@ class Router:
         for var in kwargs:
             if var in _allowed_settings:
                 if var in _int_settings:
-                    _casted_value = int(kwargs[var])
-                    setattr(self, var, _casted_value)
+                    if kwargs[var] is None:
+                        setattr(self, var, None)
+                    else:
+                        setattr(self, var, int(kwargs[var]))
                 elif var == "routing_groups":
                     self._routing_groups_input = kwargs[var]
                     rebuild_routing_groups = True
diff --git a/tests/router_unit_tests/test_router_helper_utils.py b/tests/router_unit_tests/test_router_helper_utils.py
index 65d9d6b925d..16ce731ff37 100644
--- a/tests/router_unit_tests/test_router_helper_utils.py
+++ b/tests/router_unit_tests/test_router_helper_utils.py
@@ -977,6 +977,29 @@ def test_update_settings(model_list):
     assert router.allowed_fails == 20
 
 
+def test_update_settings_none_int_values(model_list):
+    """Regression test: update_settings must not crash when None is passed for int settings.
+    Previously raised TypeError: int() argument must be a string... not 'NoneType'"""
+    router = Router(model_list=model_list, timeout=30, allowed_fails=5)
+
+    # None should reset each int setting without raising TypeError
+    router.update_settings(timeout=None)
+    assert router.timeout is None
+
+    router.update_settings(allowed_fails=None)
+    assert router.allowed_fails is None
+
+    router.update_settings(num_retries=None)
+    assert router.num_retries is None
+
+    router.update_settings(cooldown_time=None)
+    assert router.cooldown_time is None
+
+    # Valid int values must still work after None resets
+    router.update_settings(timeout=60)
+    assert router.timeout == 60
+
+
 def test_common_checks_available_deployment(model_list):
     """Test if the 'common_checks_available_deployment' function is working correctly"""
     router = Router(model_list=model_list)