diff --git a/process/DuplicateScanner_lib/process.js b/process/DuplicateScanner_lib/process.js
index 12420f6405cb18d5f9cb26dca6c86850f9df5380..b8f14e5ecaf139dbf64b8747adac1f6cc171481c 100644
--- a/process/DuplicateScanner_lib/process.js
+++ b/process/DuplicateScanner_lib/process.js
@@ -1107,12 +1107,11 @@ _DuplicateScannerUtils._migrateParticipantsToNewContact = function (pTableName,
         .where([pTableName, pContactIdColumn], pTargetContactId)
         .arrayColumn();
 
-    var updateCount = newWhere([pTableName, pAssignableIdColumn], excludedIds, SqlBuilder.NOT_IN())
+    var updateCount = newWhereIfSet([pTableName, pAssignableIdColumn], excludedIds, SqlBuilder.NOT_IN())
         .and([pTableName, pContactIdColumn], pSourceContactId)
         .updateFields(new Map().set(pContactIdColumn, pTargetContactId), pTableName);
         
-    var deleteCount = newWhere([pTableName, pAssignableIdColumn], excludedIds, SqlBuilder.IN())
-        .and([pTableName, pContactIdColumn], pSourceContactId)
+    var deleteCount = newWhere([pTableName, pContactIdColumn], pSourceContactId)
         .tableName(pTableName)
         .deleteData();