diff --git a/src/EFCore.Relational/Extensions/RelationalPropertyExtensions.cs b/src/EFCore.Relational/Extensions/RelationalPropertyExtensions.cs
index 187f3297208..157dc23d827 100644
--- a/src/EFCore.Relational/Extensions/RelationalPropertyExtensions.cs
+++ b/src/EFCore.Relational/Extensions/RelationalPropertyExtensions.cs
@@ -1145,7 +1145,7 @@ public static void SetIsFixedLength(this IMutableProperty property, bool? fixedL
     /// <returns><see langword="true" /> if the mapped column is nullable; <see langword="false" /> otherwise.</returns>
     public static bool IsColumnNullable(this IReadOnlyProperty property)
         => property.IsNullable
-            || (property.DeclaringType is IReadOnlyEntityType entityType
+            || (property.DeclaringType.ContainingEntityType is IReadOnlyEntityType entityType
                 && entityType.BaseType != null
                 && entityType.GetMappingStrategy() == RelationalAnnotationNames.TphMappingStrategy);
 
diff --git a/test/EFCore.Relational.Tests/ModelBuilding/RelationalModelBuilderTest.cs b/test/EFCore.Relational.Tests/ModelBuilding/RelationalModelBuilderTest.cs
index a888a5810ae..d0fb6786d21 100644
--- a/test/EFCore.Relational.Tests/ModelBuilding/RelationalModelBuilderTest.cs
+++ b/test/EFCore.Relational.Tests/ModelBuilding/RelationalModelBuilderTest.cs
@@ -341,6 +341,30 @@ public virtual void Configuring_direction_on_RowsAffectedParameter_throws()
 
     public abstract class RelationalComplexTypeTestBase : ComplexTypeTestBase
     {
+        [ConditionalFact]
+        public virtual void Can_use_TPH()
+        {
+            var modelBuilder = CreateModelBuilder();
+
+            modelBuilder
+                .Ignore<Product>()
+                .Ignore<IndexedClass>()
+                .Entity<ComplexPropertiesBase>();
+
+            modelBuilder
+                .Entity<ComplexProperties>()
+                .ComplexProperty(e => e.Customer)
+                .Ignore(c => c.Details)
+                .Ignore(c => c.Orders)
+                .Property(c => c.Name).IsRequired();
+
+            var model = modelBuilder.FinalizeModel();
+            var complexProperty = model.FindEntityType(typeof(ComplexProperties))!.GetComplexProperties().Single();
+            var property = complexProperty.ComplexType.FindProperty(nameof(Customer.Name))!;
+
+            Assert.True(property.IsColumnNullable());
+        }
+
         [ConditionalFact]
         public virtual void Can_use_table_splitting()
         {
diff --git a/test/EFCore.Tests/ModelBuilding/TestModel.cs b/test/EFCore.Tests/ModelBuilding/TestModel.cs
index 037a7e5f685..8aa6a51e038 100644
--- a/test/EFCore.Tests/ModelBuilding/TestModel.cs
+++ b/test/EFCore.Tests/ModelBuilding/TestModel.cs
@@ -894,9 +894,13 @@ protected interface IReplaceable
         int Property { get; set; }
     }
 
-    protected class ComplexProperties
+    protected class ComplexPropertiesBase
     {
         public int Id { get; set; }
+    }
+
+    protected class ComplexProperties : ComplexPropertiesBase
+    {
         public required Customer Customer { get; set; }
         public required DoubleProperty DoubleProperty { get; set; }
         public required IndexedClass IndexedClass { get; set; }