diff --git a/vllm/engine/output_processor/multi_step.py b/vllm/engine/output_processor/multi_step.py
index 5f126c7571dc..126e7da70216 100644
--- a/vllm/engine/output_processor/multi_step.py
+++ b/vllm/engine/output_processor/multi_step.py
@@ -178,7 +178,7 @@ def _process_seq_outputs(self, seq: Sequence,
         # generates a fixed number of tokens without evaluating stopping
         # conditions within the block. This can cause an eos token to be
         # unintentionally ignored.
-        if not sampling_params.ignore_eos:
+        if not sampling_params.ignore_eos and self.detokenizer:
             eos_token_id = self.get_tokenizer_for_seq(seq).eos_token_id
             # Avoiding .index calls as exception throwing in the happy path
             # is expensive.