diff --git a/dist_run.py b/dist_run.py
index bc3badbc4..1580f19b1 100644
--- a/dist_run.py
+++ b/dist_run.py
@@ -10,6 +10,7 @@
 
 import argparse
 import os
+from enum import auto, Enum
 from pathlib import Path
 from types import SimpleNamespace
 from typing import Any, Dict, List, Optional, Tuple
@@ -49,6 +50,7 @@
 
 
 logger = SingletonLogger.get_logger()
+_tokenizer_type = None  # global variable to store the tokenizer type
 
 # Using model name to identify the model to load, for example "llama2-7b-chat".
 # You can change it to other values listed below.
@@ -59,6 +61,11 @@
 }
 
 
+class TokenizerType(Enum):
+    Tiktoken = auto()
+    SentencePiece = auto()
+
+
 def _init_distributed():
     dist.init_process_group("nccl")
     rank = dist.get_rank()
@@ -80,7 +87,10 @@ def _build_chat_tokenizer(
     model_name: str,
     model_base_name: Optional[str] = None,
 ) -> SentencePieceProcessor | TiktokenTokenizer:
-    """Builds a tokenizer for the given model name."""
+    """Builds a tokenizer for the given model name, and sets the global tokenizer type variable"""
+
+    global _tokenizer_type
+
     # Try to infer the model base name from the model name:
     # e.g. "llama2-7b-chat" -> "llama2"
     if model_base_name is None:
@@ -107,6 +117,15 @@ def _build_chat_tokenizer(
     logger.info(
         f"using tokenizer = {tokenizer.__class__.__module__}.{tokenizer.__class__.__name__}"
     )
+    # set global variable _tokenizer_type
+    if isinstance(tokenizer, TiktokenTokenizer):
+        _tokenizer_type = TokenizerType.Tiktoken
+    elif isinstance(tokenizer, SentencePieceProcessor):
+        _tokenizer_type = TokenizerType.SentencePiece
+    else:
+        raise ValueError(f"Unknown tokenizer type: {tokenizer.__class__}")
+
+    logger.info(f"tokenizer type = {_tokenizer_type}")
     return tokenizer
 
 
@@ -269,6 +288,7 @@ def _cleanup():
 
 prompt = [
     "What is Snow?",
+    # "Can you explain what is the purpose of back propagation in neural networks?",
     "Who is Santa Claus?",
     "Where does Santa live?",
     # "Who is Abraham Lincoln?",
@@ -487,7 +507,7 @@ def get_example_ins_outs(seqlen: int) -> Tuple[torch.Tensor, torch.Tensor]:
         group=pp_group,
     )
     # create schedule
-    decorder = ScheduleGPipe(decode_stage, 1)
+    decoder = ScheduleGPipe(decode_stage, 1)
 
     # Decoding
     with torch.no_grad(), CUDATrackTime() as timer:
@@ -510,11 +530,11 @@ def get_example_ins_outs(seqlen: int) -> Tuple[torch.Tensor, torch.Tensor]:
 
             # Run data through pipeline
             if pp_rank == first_pp_rank:
-                output = decorder.step(new_token, **kwargs)
+                output = decoder.step(new_token, **kwargs)
             elif pp_rank == last_pp_rank:
-                output = decorder.step(**kwargs)
+                output = decoder.step(**kwargs)
             else:  # middle pp ranks
-                decorder.step(**kwargs)
+                decoder.step(**kwargs)
 
             # Decode the output
             if pp_rank == last_pp_rank:
@@ -539,13 +559,16 @@ def get_example_ins_outs(seqlen: int) -> Tuple[torch.Tensor, torch.Tensor]:
         # token ids. Thus cat'ing along dim 1.
         res = torch.cat(res, dim=1)
         res_list = res.tolist()
-        if isinstance(tokenizer, TiktokenTokenizer):
+        if _tokenizer_type == TokenizerType.Tiktoken:
             # For TiktokenTokenizer, we need to decode prompt by prompt.
             # TODO: is there a better way to do this?
             responses = [tokenizer.decode(sequence) for sequence in res_list]
-        else:  # SentencePieceProcessor
+        elif _tokenizer_type == TokenizerType.SentencePiece:  # SentencePieceProcessor
             # For SentencePieceProcessor, we can decode the entire 2D list at once.
             responses = tokenizer.decode(res_list)
+        else:
+            raise ValueError(f"Unknown tokenizer type {_tokenizer_type}")
+
         # Show prompts and responses
         for prompt_text, response_text in zip(prompt, responses):
             logger.info(f"Prompt: {color.green}{prompt_text} {color.reset}")