diff --git a/superx/WEB-INF/conf/edustore/db/install/upgrade/kernmodul_upgrade_man.sql b/superx/WEB-INF/conf/edustore/db/install/upgrade/kernmodul_upgrade_man.sql
index e4bc31f..e9a5a0b 100644
--- a/superx/WEB-INF/conf/edustore/db/install/upgrade/kernmodul_upgrade_man.sql
+++ b/superx/WEB-INF/conf/edustore/db/install/upgrade/kernmodul_upgrade_man.sql
@@ -193,4 +193,5 @@ drop table tmp_dummy;
 --obsolete Zeilen weg:
 delete from sachgeb_maske_bez where maskeninfo_id is null;
 
-
+update userinfo set gueltig_von=date_val('01.01.1900') where gueltig_von is null;
+update userinfo set gueltig_bis=date_val('01.01.2900') where gueltig_bis is null;
\ No newline at end of file