diff -r dab538127d72 -r 08dc10ef9ab1 migration.py
--- a/migration.py	Tue Sep 23 13:51:12 2014 +0200
+++ b/migration.py	Fri Sep 19 13:08:26 2014 +0200
@@ -524,7 +524,7 @@
                 self.errors.append( ('add', cube, version, source) )
             elif versions:
                 lower_strict = version_strictly_lower(self.cubes[cube], version)
-                if oper in ('>=','='):
+                if oper in ('>=','=','=='):
                     if lower_strict:
                         self.errors.append( ('update', cube, version, source) )
                 elif oper is None: