diff --git a/serve/mlc_serve/api/handler.py b/serve/mlc_serve/api/handler.py
index 3de28fe3b5..1ac19de062 100644
--- a/serve/mlc_serve/api/handler.py
+++ b/serve/mlc_serve/api/handler.py
@@ -73,7 +73,6 @@ def _get_sampling_params(
         sampling_params.logprobs = request.logprobs
     if request.response_format and request.response_format.type == "json_object":
         sampling_params.json_schema = request.response_format.response_schema
-
     sampling_params.vocab_size = model_artifact_config.vocab_size
     return sampling_params
 
diff --git a/serve/mlc_serve/engine/engine_common.py b/serve/mlc_serve/engine/engine_common.py
index 1fe341867e..acf1faa90d 100644
--- a/serve/mlc_serve/engine/engine_common.py
+++ b/serve/mlc_serve/engine/engine_common.py
@@ -263,14 +263,7 @@ def get_requests_to_process(
 
     if is_prompt_batch:
         for state in current_states:
-<<<<<<< HEAD
             if is_evicted_parallel_sampling_request(state):
-=======
-            if not state.is_prefilled:
-                # `JSONLogitsProcessor` needs to be created only once.
-                if state.sampling_params.json_schema is not None:
-                    state.sampling_params.logits_processor = JSONLogitsProcessor(state.sampling_params.json_schema, tokenizer._tokenizer)
->>>>>>> works
                 requests.append(
                     PrefillRequest(
                         request_id=state.request_id,
@@ -299,6 +292,12 @@ def get_requests_to_process(
                 # TODO(masahi): How to account for token counts in EvalMultiQueryRequest in
                 # Prometheus metric?
             elif not state.is_prefilled:
+                # `JSONLogitsProcessor` needs to be created only once.
+                if state.sampling_params.json_schema is not None:
+                    state.sampling_params.logits_processor = JSONLogitsProcessor(
+                        state.sampling_params.json_schema, tokenizer._tokenizer
+                    )
+
                 if (
                     state.num_sequences == 1
                     and state.generation_sequences[0].generated_token_ids
@@ -317,14 +316,7 @@ def get_requests_to_process(
                         request_id=state.request_id,
                         token_ids=token_ids,
                         num_sequence=state.num_sequences,
-<<<<<<< HEAD
                         sampling_params=state.sampling_params,
-                        logit_processor=JSONLogitsProcessor(
-                            state.sampling_params.json_schema, tokenizer._tokenizer
-                        ),
-=======
-                        sampling_params=state.sampling_params
->>>>>>> works
                     )
                 )
 
@@ -346,12 +338,6 @@ def get_requests_to_process(
                             prompt_token_counts=prompt_counts,
                             token_ids=gen_seq.generated_token_ids,
                             sampling_params=state.sampling_params,
-<<<<<<< HEAD
-                            logit_processor=JSONLogitsProcessor(
-                                state.sampling_params.json_schema, tokenizer._tokenizer
-                            ),
-=======
->>>>>>> works
                         )
                     )
                     cache_manager.extend(
diff --git a/serve/mlc_serve/model/model_common.py b/serve/mlc_serve/model/model_common.py
index 1dda0cee94..d5a010e4e5 100644
--- a/serve/mlc_serve/model/model_common.py
+++ b/serve/mlc_serve/model/model_common.py
@@ -14,6 +14,7 @@
 )
 from ..engine.model_module import (
     PrefillRequest,
+    DecodeRequest,
     EvalMultiQueryRequest,
     RequestType,
     TextGenerationResult,
@@ -97,6 +98,17 @@ def sample_from_logits(
     # synchronization point for sampling tensors
     # wait until all the tensors are loaded on GPU
     torch.cuda.current_stream().wait_stream(copy_stream)
+
+    # Logit processing for constraint sampling e.g., JSON Mode
+    for i, (sequence_id, request) in enumerate(zip(sequence_ids, requests)):
+        if request.sampling_params.logits_processor is not None:
+            cs_input_ids = (
+                request.token_ids if isinstance(request, DecodeRequest) else []
+            )
+            logits[i] = request.sampling_params.logits_processor(
+                sequence_id, cs_input_ids, logits[i]
+            )
+
     logits = adjust_logits(logits, sampling_metadata, vocab_size)
     outputs: List[TextGenerationResult] = []