diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/misc/migration/3.21.2_Any.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/misc/migration/3.21.2_Any.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,7 @@
+sync_schema_props_perms('cwuri')
+
+helper = repo.system_source.dbhelper
+cu = session.cnxset.cu
+helper.set_null_allowed(cu, 'moved_entities', 'extid', 'VARCHAR(256)', False)
+
+commit()