diff --git a/utils.py b/utils.py
index 5153348..061c3ba 100644
--- a/utils.py
+++ b/utils.py
@@ -35,7 +35,7 @@ class ColorizeFilter(logging.Filter):
       return True
 
 def convert(data):
-    if isinstance(data, bytes):  return data.decode('ascii')
+    if isinstance(data, bytes):  return data.decode('utf-8')
     if isinstance(data, dict):   return dict(map(convert, data.items()))
     if isinstance(data, tuple):  return map(convert, data)
     json_data = json.dumps(data)