diff --git a/backend/src/Squidex.Infrastructure/CollectionExtensions.cs b/backend/src/Squidex.Infrastructure/CollectionExtensions.cs
index f4be61d44..51fe2ca6a 100644
--- a/backend/src/Squidex.Infrastructure/CollectionExtensions.cs
+++ b/backend/src/Squidex.Infrastructure/CollectionExtensions.cs
@@ -15,12 +15,12 @@ namespace Squidex.Infrastructure
     {
         public static bool SetEquals<T>(this IReadOnlyCollection<T> source, IReadOnlyCollection<T> other)
         {
-            return source.Intersect(other).Count() == other.Count;
+            return source.Count == other.Count && source.Intersect(other).Count() == other.Count;
         }
 
         public static bool SetEquals<T>(this IReadOnlyCollection<T> source, IReadOnlyCollection<T> other, IEqualityComparer<T> comparer)
         {
-            return source.Intersect(other, comparer).Count() == other.Count;
+            return source.Count == other.Count && source.Intersect(other, comparer).Count() == other.Count;
         }
 
         public static IResultList<T> SortSet<T, TKey>(this IResultList<T> input, Func<T, TKey> idProvider, IReadOnlyList<TKey> ids) where T : class
diff --git a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/EventSynchronization/SchemaSynchronizerTests.cs b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/EventSynchronization/SchemaSynchronizerTests.cs
index f60d7364f..ed8ab0d7f 100644
--- a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/EventSynchronization/SchemaSynchronizerTests.cs
+++ b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/EventSynchronization/SchemaSynchronizerTests.cs
@@ -627,5 +627,27 @@ namespace Squidex.Domain.Apps.Core.Operations.EventSynchronization
                 new SchemaFieldsReordered { FieldIds = new List<long> { 10, 50, 11 } }
             );
         }
+
+        [Fact]
+        public void Should_create_events_if_field_renamed()
+        {
+            var sourceSchema =
+                new Schema("source")
+                    .AddString(10, "f1", Partitioning.Invariant)
+                    .AddString(11, "f2", Partitioning.Invariant);
+
+            var targetSchema =
+                new Schema("target")
+                    .AddString(1, "f3", Partitioning.Invariant)
+                    .AddString(2, "f2", Partitioning.Invariant);
+
+            var events = sourceSchema.Synchronize(targetSchema, idGenerator);
+
+            events.ShouldHaveSameEvents(
+                new FieldDeleted { FieldId = NamedId.Of(10L, "f1") },
+                new FieldAdded { FieldId = NamedId.Of(50L, "f3"), Name = "f3", Partitioning = Partitioning.Invariant.Key, Properties = new StringFieldProperties() },
+                new SchemaFieldsReordered { FieldIds = new List<long> { 50, 11 } }
+            );
+        }
     }
 }
diff --git a/backend/tests/Squidex.Infrastructure.Tests/CollectionExtensionsTests.cs b/backend/tests/Squidex.Infrastructure.Tests/CollectionExtensionsTests.cs
index 7e074b05c..50bd498d5 100644
--- a/backend/tests/Squidex.Infrastructure.Tests/CollectionExtensionsTests.cs
+++ b/backend/tests/Squidex.Infrastructure.Tests/CollectionExtensionsTests.cs
@@ -15,6 +15,26 @@ namespace Squidex.Infrastructure
         private readonly Dictionary<int, int> valueDictionary = new Dictionary<int, int>();
         private readonly Dictionary<int, List<int>> listDictionary = new Dictionary<int, List<int>>();
 
+        [Fact]
+        public void SetEquals_should_return_false_when_subset()
+        {
+            var set1 = new[] { 1, 2 };
+            var set2 = new[] { 1, 2, 3 };
+
+            Assert.False(set1.SetEquals(set2));
+            Assert.False(set2.SetEquals(set1));
+        }
+
+        [Fact]
+        public void SetEquals_should_return_true_for_same_items_in_different_order()
+        {
+            var set1 = new[] { 1, 2, 3 };
+            var set2 = new[] { 3, 2, 1 };
+
+            Assert.True(set1.SetEquals(set2));
+            Assert.True(set2.SetEquals(set1));
+        }
+
         [Fact]
         public void IndexOf_should_return_index_when_found()
         {