diff --git a/supervisor/compat.py b/supervisor/compat.py
index 004c00e0f..6d2185a02 100644
--- a/supervisor/compat.py
+++ b/supervisor/compat.py
@@ -51,13 +51,13 @@ def as_bytes(s, encoding='utf8'):
         if isinstance(s, bytes):
             return s
         else:
-            return s.encode(encoding)
+            return s.encode(encoding, errors='replace')
 
     def as_string(s, encoding='utf8'):
         if isinstance(s, str):
             return s
         else:
-            return s.decode(encoding)
+            return s.decode(encoding, errors='replace')
 
     def is_text_stream(stream):
         import _io