diff --git a/src/main/java/org/gcube/accounting/persistence/AccountingPersistenceBackendMonitor.java b/src/main/java/org/gcube/accounting/persistence/AccountingPersistenceBackendMonitor.java
index 0563f62..699a21e 100644
--- a/src/main/java/org/gcube/accounting/persistence/AccountingPersistenceBackendMonitor.java
+++ b/src/main/java/org/gcube/accounting/persistence/AccountingPersistenceBackendMonitor.java
@@ -79,12 +79,14 @@ public class AccountingPersistenceBackendMonitor implements Runnable {
 		}
 		
 		if(elaborationFile!=null){
-			elaborateFile(elaborationFile);
-			boolean deleted = elaborationFile.delete();
-			if(!deleted){
-				logger.debug("Failed to delete file {}", elaborationFile.getAbsolutePath());
-				File elaborationFileNotDeleted = new File(elaborationFile.getAbsolutePath()+ELABORATION_FILE_NOT_DELETED_SUFFIX);
-				elaborationFile.renameTo(elaborationFileNotDeleted);
+			synchronized (elaborationFile) {
+				elaborateFile(elaborationFile);
+				boolean deleted = elaborationFile.delete();
+				if(!deleted){
+					logger.debug("Failed to delete file {}", elaborationFile.getAbsolutePath());
+					File elaborationFileNotDeleted = new File(elaborationFile.getAbsolutePath()+ELABORATION_FILE_NOT_DELETED_SUFFIX);
+					elaborationFile.renameTo(elaborationFileNotDeleted);
+				}
 			}
 			
 		}