diff --git a/db/zm_update-1.31.37.sql b/db/zm_update-1.31.37.sql
index 0d66e0282..866fd9330 100644
--- a/db/zm_update-1.31.37.sql
+++ b/db/zm_update-1.31.37.sql
@@ -46,4 +46,4 @@ FOR EACH ROW
 
 //
 
-UPDATE Storage SET DiskSpace=(SELECT SUM(DiskSpace) FROM Events WHERE StorageId=Storage.Id)//
+UPDATE Storage SET DiskSpace=(SELECT SUM(COALESCE(DiskSpace,0)) FROM Events WHERE StorageId=Storage.Id)//