diff --git a/gramps/gen/merge/diff.py b/gramps/gen/merge/diff.py
index f80dfa551..dd8fe3cec 100644
--- a/gramps/gen/merge/diff.py
+++ b/gramps/gen/merge/diff.py
@@ -33,6 +33,7 @@ from ..plug import BasePluginManager
 from ..db.dictionary import DictionaryDb
 from gramps.gen.lib.handle import Handle
 from ..const import GRAMPS_LOCALE as glocale
+from ..constfunc import handle2internal
 _ = glocale.translation.gettext
 
 def import_as_dict(filename, user=None):
@@ -142,8 +143,8 @@ def diff_dbs(db1, db2, user=None):
         for item in ['Person', 'Family', 'Source', 'Citation', 'Event', 'Media',
                      'Place', 'Repository', 'Note', 'Tag']:
             step()
-            handles1 = sorted(db1._tables[item]["handles_func"]())
-            handles2 = sorted(db2._tables[item]["handles_func"]())
+            handles1 = sorted([handle2internal(handle) for handle in db1._tables[item]["handles_func"]()])
+            handles2 = sorted([handle2internal(handle) for handle in db2._tables[item]["handles_func"]()])
             p1 = 0
             p2 = 0
             while p1 < len(handles1) and p2 < len(handles2):