diff --git a/speechserving/speechserving/conf/asr/asr.yaml b/speechserving/speechserving/conf/asr/asr.yaml
index 87405155..cfa3a68f 100644
--- a/speechserving/speechserving/conf/asr/asr.yaml
+++ b/speechserving/speechserving/conf/asr/asr.yaml
@@ -1,5 +1,4 @@
 model: 'conformer_wenetspeech'
-lang: 'conformer_wenetspeech'
 lang: 'zh'
 sample_rate: 16000
 decode_method: 'attention_rescoring'
diff --git a/speechserving/speechserving/restful/api.py b/speechserving/speechserving/restful/api.py
index b3b87ea5..c5539f24 100644
--- a/speechserving/speechserving/restful/api.py
+++ b/speechserving/speechserving/restful/api.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from typing import List
 from fastapi import APIRouter
 
 from .tts_api import router as tts_router
@@ -18,7 +19,7 @@ from .asr_api import router as asr_router
 
 _router = APIRouter()
 
-def setup_router(api_list: list):
+def setup_router(api_list: List):
 
     for api_name in api_list:
         if api_name == 'asr':
diff --git a/speechserving/speechserving/utils/util.py b/speechserving/speechserving/utils/util.py
index 6e1bd26c..cf568572 100644
--- a/speechserving/speechserving/utils/util.py
+++ b/speechserving/speechserving/utils/util.py
@@ -13,7 +13,7 @@
 import base64
 
 
-def readwav2base64(wav_file):
+def wav2base64(wav_file):
     """
     read wave file and covert to base64 string
     """
@@ -23,7 +23,7 @@ def readwav2base64(wav_file):
     return base64_string
 
 
-def readbase64towav(base64_string):
+def base64towav(base64_string):
     pass