From 3952bcd381f64cd0d6cea35105e0967a8c525e8a Mon Sep 17 00:00:00 2001
From: Andriy Svyryd <Andriy.Svyryd@microsoft.com>
Date: Mon, 3 Nov 2025 13:43:11 -0800
Subject: [PATCH] Fix parameter type for ComplexCollection and ComplexProperty
 entry methods

Fixes #37064
---
 src/EFCore/ChangeTracking/ComplexElementEntry`.cs        | 2 +-
 src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs       | 2 +-
 .../ChangeTracking/Internal/InternalComplexEntryTest.cs  | 9 ++++++++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/EFCore/ChangeTracking/ComplexElementEntry`.cs b/src/EFCore/ChangeTracking/ComplexElementEntry`.cs
index 01b51169e63..fc78ac03500 100644
--- a/src/EFCore/ChangeTracking/ComplexElementEntry`.cs
+++ b/src/EFCore/ChangeTracking/ComplexElementEntry`.cs
@@ -124,7 +124,7 @@ public virtual ComplexPropertyEntry<TEntity, TNestedComplexProperty> ComplexProp
     /// </param>
     /// <returns>An object that exposes change tracking information and operations for the given property.</returns>
     public virtual ComplexCollectionEntry<TEntity, TElement> ComplexCollection<TElement>(
-        Expression<Func<TEntity, IEnumerable<TElement>?>> propertyExpression)
+        Expression<Func<TComplexProperty, IEnumerable<TElement>?>> propertyExpression)
         where TElement : notnull
     {
         Check.NotNull(propertyExpression, nameof(propertyExpression));
diff --git a/src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs b/src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs
index 0045f0a4c02..8b459f02ce6 100644
--- a/src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs
+++ b/src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs
@@ -117,7 +117,7 @@ public virtual ComplexPropertyEntry<TEntity, TNestedComplexProperty> ComplexProp
     /// </param>
     /// <returns>An object that exposes change tracking information and operations for the given property.</returns>
     public virtual ComplexCollectionEntry<TEntity, TElement> ComplexCollection<TElement>(
-        Expression<Func<TEntity, IEnumerable<TElement>?>> propertyExpression)
+        Expression<Func<TComplexProperty, IEnumerable<TElement>?>> propertyExpression)
         where TElement : notnull
     {
         Check.NotNull(propertyExpression, nameof(propertyExpression));
diff --git a/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs b/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
index ef361b1a753..3f500ae99d6 100644
--- a/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
+++ b/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
@@ -707,7 +707,7 @@ public void DetectChanges_detects_changes_in_nested_complex_collections()
         {
             Items =
             [
-                new NestedItem { Name = "bar" },
+                new NestedItem { Name = "bar1" },
                 new NestedItem { Name = "baz" },
                 new NestedItem { Name = "new-bar" }
             ]
@@ -717,6 +717,13 @@ public void DetectChanges_detects_changes_in_nested_complex_collections()
         changeDetector.DetectChanges(stateManager);
 
         Assert.Equal(EntityState.Modified, entityEntry.EntityState);
+
+        var nestedJson = new EntityEntry<BlogWithNested>(entityEntry).ComplexProperty(b => b.NestedJson);
+        var items = nestedJson.ComplexCollection(j => j.Items);
+        Assert.Equal(3, items.CurrentValue!.Count);
+        Assert.Equal(EntityState.Modified, items[0].State);
+        Assert.Equal(EntityState.Unchanged, items[1].State);
+        Assert.Equal(EntityState.Added, items[2].State);
     }
 
     private static IModel CreateModel()