diff --git a/K100-vLLM-Patched-v2.0/fix_tokenizer.py b/K100-vLLM-Patched-v2.0/fix_tokenizer.py
index 80d79f6..10fbba5 100644
--- a/K100-vLLM-Patched-v2.0/fix_tokenizer.py
+++ b/K100-vLLM-Patched-v2.0/fix_tokenizer.py
@@ -2,6 +2,8 @@ import os
 import shutil
 import json
 import sys
+import transformers
+import inspect
 sys.path.insert(0, '/opt')
 from detect_tokenizer import detect
 
@@ -35,22 +37,28 @@ if os.path.exists(cfg_path):
 else:
     cfg = {}
 
-if typ == "fast":
-    cfg["tokenizer_class"] = "PreTrainedTokenizerFast"
-elif typ == "sentencepiece":
-    cfg["tokenizer_class"] = "LlamaTokenizer"
-elif typ == "bpe":
-    cfg["tokenizer_class"] = "GPT2TokenizerFast" 
+VALID_CLASSES = {
+    name for name, obj in inspect.getmembers(transformers)
+    if inspect.isclass(obj) and "Tokenizer" in name
+}
+
+BAD_CLASSES = {"TokenizersBackend", "TiktokenTokenizer"}
+
+FALLBACK = {
+    "fast": "PreTrainedTokenizerFast",
+    "sentencepiece": "LlamaTokenizer",
+    "bpe": "GPT2TokenizerFast",
+}
+
+if orig_cls and orig_cls in VALID_CLASSES and orig_cls not in BAD_CLASSES:
+    print(f"[fix_tokenizer] tokenizer_class '{orig_cls}' is valid, skip override")
 else:
-    cfg["tokenizer_class"] = "PreTrainedTokenizerFast"
-
-bad_classes = [
-    "TokenizersBackend",
-    "TiktokenTokenizer",
-]
-
-if orig_cls in bad_classes:
-    print(f"[fix] override bad tokenizer_class: {orig_cls} → {cfg['tokenizer_class']}")     
+    fallback = FALLBACK.get(typ, "PreTrainedTokenizerFast")
+    if orig_cls:
+        print(f"[fix] override bad tokenizer_class: {orig_cls} → {fallback}")
+    else:
+        print(f"[fix] tokenizer_class missing, set to: {fallback}")
+    cfg["tokenizer_class"] = fallback
 
 with open(cfg_path, "w") as f:
     json.dump(cfg, f)