diff --git a/vllm/engine/llm_engine.py b/vllm/engine/llm_engine.py
index 94aed6b8c50c7..f72902c372181 100644
--- a/vllm/engine/llm_engine.py
+++ b/vllm/engine/llm_engine.py
@@ -1302,6 +1302,11 @@ class LLMEngine:
             raise NotImplementedError(
                 "Pipeline parallelism is only supported through AsyncLLMEngine "
                 "as performance will be severely degraded otherwise.")
+
+        if self.scheduler_config.num_scheduler_steps > 1:
+            raise NotImplementedError(
+                "Multiple scheduler steps (multi-step) are only supported "
+                "through AsyncLLMEngine. ")
         seq_group_metadata_list, scheduler_outputs = self.scheduler[
             0].schedule()