diff --git a/Database/AthenaPOOL/OutputStreamAthenaPool/python/MultipleStreamManager.py b/Database/AthenaPOOL/OutputStreamAthenaPool/python/MultipleStreamManager.py
index 579b3808d9149c0d048e0c240f786eb96beedc80..13f881537618e45889d22f0dbd20bafcdd705f86 100644
--- a/Database/AthenaPOOL/OutputStreamAthenaPool/python/MultipleStreamManager.py
+++ b/Database/AthenaPOOL/OutputStreamAthenaPool/python/MultipleStreamManager.py
@@ -571,7 +571,7 @@ class MultipleStreamManager:
         theStream.Stream.HelperTools += [ streamMarkUpTool ]
         theStream.Stream.WritingTool.SubLevelBranchName = "<key>"
         svcMgr.AthenaPoolCnvSvc.PoolAttributes += [ "DatabaseName = '" + FileName + "'; COMPRESSION_LEVEL = '5'" ]
-        svcMgr.AthenaPoolCnvSvc.PoolAttributes += [ "DatabaseName = '" + FileName + "'; ContainerName = 'TTree=CollectionTree'; TREE_AUTO_FLUSH = '-10000000'" ]
+        svcMgr.AthenaPoolCnvSvc.PoolAttributes += [ "DatabaseName = '" + FileName + "'; ContainerName = 'TTree=CollectionTree'; TREE_AUTO_FLUSH = '-20000000'" ]
         svcMgr.AthenaPoolCnvSvc.PoolAttributes += [ "DatabaseName = '" + FileName + "'; ContainerName = 'TTree=CollectionTree'; CONTAINER_SPLITLEVEL = '1'" ]
         svcMgr.AthenaPoolCnvSvc.PoolAttributes += [ "DatabaseName = '" + FileName + "'; ContainerName = 'TTree=Aux.'; CONTAINER_SPLITLEVEL = '1'"]
         return theStream