diff --git a/beets/mediafile.py b/beets/mediafile.py
index 8c9e63e9b..db6261185 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -491,6 +491,7 @@ class MediaField(object):
                 for frame in frames:
                     if frame.desc.lower() == style.id3_desc.lower():
                         setattr(frame, style.id3_frame_field, out)
+                        frame.encoding = 3   # utf8
                         found = True
                         break