diff --git a/src/maxtext/inference/vllm_decode.py b/src/maxtext/inference/vllm_decode.py
index 5908ab2e2a..422a2be04f 100644
--- a/src/maxtext/inference/vllm_decode.py
+++ b/src/maxtext/inference/vllm_decode.py
@@ -93,7 +93,7 @@ def decode_with_vllm(config: Config) -> None:
       "additional_config": {
           "maxtext_config": {
               "model_name": config.model_name,
-              "weight_dtype": config.weight_dtype,
+              "weight_dtype": config.weight_dtype.name,
               "allow_split_physical_axes": True,
               "debug_sharding": config.debug_sharding,
               "prefuse_moe_weights": config.prefuse_moe_weights,
@@ -250,7 +250,7 @@ def decode_with_tunix(
   rollout_vllm_additional_config = {
       "maxtext_config": {
           "model_name": config.model_name,
-          "weight_dtype": config.weight_dtype,
+          "weight_dtype": config.weight_dtype.name,
           "allow_split_physical_axes": True,
           "debug_sharding": config.debug_sharding,
           "prefuse_moe_weights": config.prefuse_moe_weights,