diff --git a/src/DataAccess/src/SIL.DataAccess/IUpdateBuilder.cs b/src/DataAccess/src/SIL.DataAccess/IUpdateBuilder.cs
index 6eaf27e5..35db6f88 100644
--- a/src/DataAccess/src/SIL.DataAccess/IUpdateBuilder.cs
+++ b/src/DataAccess/src/SIL.DataAccess/IUpdateBuilder.cs
@@ -24,6 +24,7 @@ IUpdateBuilder<T> SetAll<TItem, TField>(
         Expression<Func<T, IEnumerable<TItem>?>> collectionField,
         Expression<Func<TItem, TField>> itemField,
         TField value,
-        Expression<Func<TItem, bool>>? predicate = null
+        Expression<Func<TItem, bool>>? predicate = null,
+        Expression<Func<T, object>>? setIfFieldExists = null
     );
 }
diff --git a/src/DataAccess/src/SIL.DataAccess/MemoryUpdateBuilder.cs b/src/DataAccess/src/SIL.DataAccess/MemoryUpdateBuilder.cs
index bbf6b5d9..a6131d63 100644
--- a/src/DataAccess/src/SIL.DataAccess/MemoryUpdateBuilder.cs
+++ b/src/DataAccess/src/SIL.DataAccess/MemoryUpdateBuilder.cs
@@ -170,9 +170,11 @@ public IUpdateBuilder<T> SetAll<TItem, TField>(
         Expression<Func<T, IEnumerable<TItem>?>> collectionField,
         Expression<Func<TItem, TField>> itemField,
         TField value,
-        Expression<Func<TItem, bool>>? predicate = null
+        Expression<Func<TItem, bool>>? predicate = null,
+        Expression<Func<T, object>>? setIfFieldExists = null
     )
     {
+        // TODO check for setIfFieldExists
         (IEnumerable<object> owners, PropertyInfo? prop, object? index) = GetFieldOwners(
             _entity,
             _filter,
diff --git a/src/DataAccess/src/SIL.DataAccess/MongoRepository.cs b/src/DataAccess/src/SIL.DataAccess/MongoRepository.cs
index d5b09a1b..b822ba38 100644
--- a/src/DataAccess/src/SIL.DataAccess/MongoRepository.cs
+++ b/src/DataAccess/src/SIL.DataAccess/MongoRepository.cs
@@ -122,7 +122,11 @@ await _collection
         var updateBuilder = new MongoUpdateBuilder<T>();
         update(updateBuilder);
         updateBuilder.Inc(e => e.Revision, 1);
-        (UpdateDefinition<T> updateDef, IReadOnlyList<ArrayFilterDefinition> arrayFilters) = updateBuilder.Build();
+        (
+            FilterDefinition<T> filterDef,
+            UpdateDefinition<T> updateDef,
+            IReadOnlyList<ArrayFilterDefinition> arrayFilters
+        ) = updateBuilder.Build(filter);
         var options = new FindOneAndUpdateOptions<T>
         {
             IsUpsert = upsert,
@@ -136,13 +140,13 @@ await _collection
             if (_context.Session is not null)
             {
                 entity = await _collection
-                    .FindOneAndUpdateAsync(_context.Session, filter, updateDef, options, cancellationToken)
+                    .FindOneAndUpdateAsync(_context.Session, filterDef, updateDef, options, cancellationToken)
                     .ConfigureAwait(false);
             }
             else
             {
                 entity = await _collection
-                    .FindOneAndUpdateAsync(filter, updateDef, options, cancellationToken)
+                    .FindOneAndUpdateAsync(filterDef, updateDef, options, cancellationToken)
                     .ConfigureAwait(false);
             }
         }
@@ -162,7 +166,11 @@ public async Task<int> UpdateAllAsync(
         var updateBuilder = new MongoUpdateBuilder<T>();
         update(updateBuilder);
         updateBuilder.Inc(e => e.Revision, 1);
-        (UpdateDefinition<T> updateDef, IReadOnlyList<ArrayFilterDefinition> arrayFilters) = updateBuilder.Build();
+        (
+            FilterDefinition<T> filterDef,
+            UpdateDefinition<T> updateDef,
+            IReadOnlyList<ArrayFilterDefinition> arrayFilters
+        ) = updateBuilder.Build(filter);
         UpdateOptions? updateOptions = null;
         if (arrayFilters.Count > 0)
             updateOptions = new UpdateOptions { ArrayFilters = arrayFilters };
@@ -172,13 +180,13 @@ public async Task<int> UpdateAllAsync(
             if (_context.Session is not null)
             {
                 result = await _collection
-                    .UpdateManyAsync(_context.Session, filter, updateDef, updateOptions, cancellationToken)
+                    .UpdateManyAsync(_context.Session, filterDef, updateDef, updateOptions, cancellationToken)
                     .ConfigureAwait(false);
             }
             else
             {
                 result = await _collection
-                    .UpdateManyAsync(filter, updateDef, updateOptions, cancellationToken)
+                    .UpdateManyAsync(filterDef, updateDef, updateOptions, cancellationToken)
                     .ConfigureAwait(false);
             }
         }
diff --git a/src/DataAccess/src/SIL.DataAccess/MongoUpdateBuilder.cs b/src/DataAccess/src/SIL.DataAccess/MongoUpdateBuilder.cs
index 662c3f92..a5fa09e5 100644
--- a/src/DataAccess/src/SIL.DataAccess/MongoUpdateBuilder.cs
+++ b/src/DataAccess/src/SIL.DataAccess/MongoUpdateBuilder.cs
@@ -4,12 +4,15 @@ public class MongoUpdateBuilder<T> : IUpdateBuilder<T>
     where T : IEntity
 {
     private readonly UpdateDefinitionBuilder<T> _builder;
+    private readonly FilterDefinitionBuilder<T> _filterBuilder;
     private readonly List<UpdateDefinition<T>> _defs;
+    private FilterDefinition<T>? _existsFilter = null;
     private readonly Dictionary<BsonDocument, (string Id, ArrayFilterDefinition<BsonValue> FilterDef)> _arrayFilters;
 
     public MongoUpdateBuilder()
     {
         _builder = Builders<T>.Update;
+        _filterBuilder = Builders<T>.Filter;
         _defs = new List<UpdateDefinition<T>>();
         _arrayFilters = new Dictionary<BsonDocument, (string, ArrayFilterDefinition<BsonValue>)>();
     }
@@ -63,13 +66,19 @@ public IUpdateBuilder<T> SetAll<TItem, TField>(
         Expression<Func<T, IEnumerable<TItem>?>> collectionField,
         Expression<Func<TItem, TField>> itemField,
         TField value,
-        Expression<Func<TItem, bool>>? predicate = null
+        Expression<Func<TItem, bool>>? predicate = null,
+        Expression<Func<T, object>>? setIfFieldExists = null
     )
     {
         Expression<Func<T, TItem>> itemExpr = ExpressionHelper.Concatenate(
             collectionField,
             (collection) => ((IReadOnlyList<TItem>?)collection)![ArrayPosition.ArrayFilter]
         );
+        FieldDefinition<T, TItem> itemFieldDef = ToFieldDefinition(itemExpr);
+        if (setIfFieldExists == null)
+        {
+            _existsFilter = _filterBuilder.Exists(setIfFieldExists, true);
+        }
         Expression<Func<T, TField>> fieldExpr = ExpressionHelper.Concatenate(itemExpr, itemField);
         if (predicate != null)
         {
@@ -107,12 +116,20 @@ public IUpdateBuilder<T> SetAll<TItem, TField>(
         return this;
     }
 
-    public (UpdateDefinition<T>, IReadOnlyList<ArrayFilterDefinition>) Build()
+    public (FilterDefinition<T>, UpdateDefinition<T>, IReadOnlyList<ArrayFilterDefinition>) Build(
+        Expression<Func<T, bool>> filter
+    )
     {
         ArrayFilterDefinition[] arrayFilters = _arrayFilters.Values.Select(f => f.FilterDef).ToArray();
+        FilterDefinition<T> outFilter;
+        if (_existsFilter != null)
+            outFilter = _filterBuilder.And(_existsFilter, filter);
+        else
+            outFilter = filter;
+
         if (_defs.Count == 1)
-            return (_defs.Single(), arrayFilters);
-        return (_builder.Combine(_defs), arrayFilters);
+            return (outFilter, _defs.Single(), arrayFilters);
+        return (outFilter, _builder.Combine(_defs), arrayFilters);
     }
 
     private static FieldDefinition<T, TField> ToFieldDefinition<TField>(
diff --git a/src/Serval/src/Serval.Translation/Services/EngineService.cs b/src/Serval/src/Serval.Translation/Services/EngineService.cs
index b0cfb5be..63e2fdd1 100644
--- a/src/Serval/src/Serval.Translation/Services/EngineService.cs
+++ b/src/Serval/src/Serval.Translation/Services/EngineService.cs
@@ -616,13 +616,15 @@ public Task UpdateDataFileFilenameFilesAsync(
                     e => e.ParallelCorpora[ArrayPosition.All].SourceCorpora[ArrayPosition.All].Files,
                     f => f.Filename,
                     filename,
-                    f => f.Id == dataFileId
+                    f => f.Id == dataFileId,
+                    f => f.ParallelCorpora
                 );
                 u.SetAll(
                     e => e.ParallelCorpora[ArrayPosition.All].TargetCorpora[ArrayPosition.All].Files,
                     f => f.Filename,
                     filename,
-                    f => f.Id == dataFileId
+                    f => f.Id == dataFileId,
+                    f => f.ParallelCorpora
                 );
             },
             cancellationToken: cancellationToken
@@ -646,13 +648,15 @@ public Task UpdateCorpusFilesAsync(
                     e => e.ParallelCorpora[ArrayPosition.All].SourceCorpora,
                     mc => mc.Files,
                     files,
-                    mc => mc.Id == corpusId
+                    f => f.Id == corpusId,
+                    f => f.ParallelCorpora
                 );
                 u.SetAll(
                     e => e.ParallelCorpora[ArrayPosition.All].TargetCorpora,
                     mc => mc.Files,
                     files,
-                    mc => mc.Id == corpusId
+                    f => f.Id == corpusId,
+                    f => f.ParallelCorpora
                 );
             },
             cancellationToken: cancellationToken