diff --git a/offlineimap/folder/Base.py b/offlineimap/folder/Base.py
index d77a16c..14b0867 100644
--- a/offlineimap/folder/Base.py
+++ b/offlineimap/folder/Base.py
@@ -920,6 +920,9 @@ class BaseFolder(object):
 
         try:
             keywordmap = dstfolder.getrepository().getkeywordmap()
+            if keywordmap is None:
+                return selfflags
+
             knownkeywords = set(keywordmap.keys())
 
             selfkeywords = self.getmessagekeywords(uid)
diff --git a/offlineimap/repository/Maildir.py b/offlineimap/repository/Maildir.py
index fef57f3..10085e7 100644
--- a/offlineimap/repository/Maildir.py
+++ b/offlineimap/repository/Maildir.py
@@ -81,7 +81,7 @@ class MaildirRepository(BaseRepository):
         return self.getconf('sep', '.').strip()
 
     def getkeywordmap(self):
-        return self.keyword2char
+        return self.keyword2char if len(self.keyword2char) > 0 else None
 
     def makefolder(self, foldername):
         """Create new Maildir folder if necessary