diff --git a/pyproject.toml b/pyproject.toml
index 66d0f88..97a4ae1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "qwen-asr"
-version = "0.0.5"
+version = "0.0.6"
 description = "Qwen-ASR python package"
 readme = "README.md"
 requires-python = ">=3.9"
diff --git a/qwen_asr/inference/qwen3_asr.py b/qwen_asr/inference/qwen3_asr.py
index d997ba3..d99b915 100644
--- a/qwen_asr/inference/qwen3_asr.py
+++ b/qwen_asr/inference/qwen3_asr.py
@@ -737,10 +737,9 @@ class Qwen3ASRModel:
                 while True:
                     end_idx = max(0, len(cur_ids) - k)
                     prefix = self.processor.tokenizer.decode(cur_ids[:end_idx]) if end_idx > 0 else ""
-                    try:
-                        prefix.encode("utf-8").decode("utf-8")
+                    if '\ufffd' not in prefix:
                         break
-                    except UnicodeError:
+                    else:
                         if end_idx == 0:
                             prefix = ""
                             break