diff --git a/trl/experimental/openenv/utils.py b/trl/experimental/openenv/utils.py
index 6d2cf850d65..70f85107be9 100644
--- a/trl/experimental/openenv/utils.py
+++ b/trl/experimental/openenv/utils.py
@@ -23,7 +23,7 @@
 
 if is_vllm_available():
     from vllm import SamplingParams
-    from vllm.sampling_params import GuidedDecodingParams
+    from vllm.sampling_params import StructuredOutputsParams
 
 
 def _build_colocate_sampling_params(
@@ -33,9 +33,9 @@ def _build_colocate_sampling_params(
     logprobs: bool = True,
 ) -> SamplingParams:
     if trainer.structured_outputs_regex:
-        guided_decoding = GuidedDecodingParams(regex=trainer.structured_outputs_regex)
+        structured_outputs = StructuredOutputsParams(regex=trainer.structured_outputs_regex)
     else:
-        guided_decoding = None
+        structured_outputs = None
 
     generation_kwargs: dict[str, Any] = {
         "n": 1,
@@ -43,7 +43,7 @@ def _build_colocate_sampling_params(
         "top_k": trainer.top_k,
         "min_p": 0.0 if trainer.min_p is None else trainer.min_p,
         "max_tokens": trainer.max_completion_length,
-        "guided_decoding": guided_decoding,
+        "structured_outputs": structured_outputs,
     }
     if trainer.repetition_penalty is not None:
         generation_kwargs["repetition_penalty"] = trainer.repetition_penalty