diff --git a/vllm/config/scheduler.py b/vllm/config/scheduler.py
index ff1ac0e18f32..88f3e62fbd4e 100644
--- a/vllm/config/scheduler.py
+++ b/vllm/config/scheduler.py
@@ -274,3 +274,8 @@ class SchedulerConfig:
             )
 
         return self
+
+    def __getattribute__(self, name: str) -> Any:
+        if name == "max_model_len" or name == "is_encoder_decoder":
+            raise AttributeError(f"{name} is an init-only parameter. ")
+        return object.__getattribute__(self, name)