diff --git a/beets/mediafile.py b/beets/mediafile.py
index 4f5be5ff4..82f6b9c06 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -460,7 +460,7 @@ class MediaField(object):
                     else:
                         if self.out_type == bool:
                             # store bools as 1,0 instead of True,False
-                            out = unicode(int(out))
+                            out = unicode(int(bool(out)))
                         elif isinstance(out, str):
                             out = out.decode('utf8', 'ignore')
                         else: