diff --git a/lib/NGCP/Schema/Result/contract_balances.pm b/lib/NGCP/Schema/Result/contract_balances.pm
index a8d42fa7..a79887ab 100644
--- a/lib/NGCP/Schema/Result/contract_balances.pm
+++ b/lib/NGCP/Schema/Result/contract_balances.pm
@@ -75,7 +75,7 @@ __PACKAGE__->belongs_to(
   {
     is_deferrable => 1,
     join_type     => "LEFT",
-    on_delete     => "CASCADE",
+    on_delete     => "SET NULL",
     on_update     => "CASCADE",
   },
 );