diff --git a/YamlDotNet/Serialization/TypeInspectors/ReadableAndWritablePropertiesTypeInspector.cs b/YamlDotNet/Serialization/TypeInspectors/ReadableAndWritablePropertiesTypeInspector.cs
index fce64cbe5..43b376cc6 100644
--- a/YamlDotNet/Serialization/TypeInspectors/ReadableAndWritablePropertiesTypeInspector.cs
+++ b/YamlDotNet/Serialization/TypeInspectors/ReadableAndWritablePropertiesTypeInspector.cs
@@ -39,8 +39,16 @@ public ReadableAndWritablePropertiesTypeInspector(ITypeInspector innerTypeDescri
 
         public override IEnumerable<IPropertyDescriptor> GetProperties(Type type, object? container)
         {
-            return innerTypeDescriptor.GetProperties(type, container)
-                .Where(p => p.CanWrite);
+            return innerTypeDescriptor
+                .GetProperties(type, container)
+                .Where(p =>
+                    p.CanWrite ||
+                    (p.Type.IsGenericType
+                        && typeof(ICollection<>)
+                            .MakeGenericType(p.Type.GenericTypeArguments[0])
+                            .IsAssignableFrom(p.Type)
+                    )
+                );
         }
     }
 }
diff --git a/YamlDotNet/Serialization/TypeInspectors/ReadablePropertiesTypeInspector.cs b/YamlDotNet/Serialization/TypeInspectors/ReadablePropertiesTypeInspector.cs
index 3e78fbc56..a229473de 100644
--- a/YamlDotNet/Serialization/TypeInspectors/ReadablePropertiesTypeInspector.cs
+++ b/YamlDotNet/Serialization/TypeInspectors/ReadablePropertiesTypeInspector.cs
@@ -36,7 +36,7 @@ public sealed class ReadablePropertiesTypeInspector : TypeInspectorSkeleton
         private readonly bool includeNonPublicProperties;
 
         public ReadablePropertiesTypeInspector(ITypeResolver typeResolver)
-            :this(typeResolver, false)
+            : this(typeResolver, false)
         {
         }
 
@@ -81,9 +81,33 @@ public ReflectionPropertyDescriptor(PropertyInfo propertyInfo, ITypeResolver typ
 
             public void Write(object target, object? value)
             {
+                if (!propertyInfo.CanWrite && value != null)
+                {
+                    var propertyCurrentValue = propertyInfo.GetValue(target);
+                    if (propertyCurrentValue != null)
+                    {
+                        var targetType = propertyInfo.PropertyType;
+                        var valueType = value.GetType();
+                        if (targetType.IsGenericType && typeof(ICollection<>).MakeGenericType(targetType.GenericTypeArguments[0]).IsAssignableFrom(targetType)
+                            && valueType.IsGenericType && typeof(ICollection<>).MakeGenericType(valueType.GenericTypeArguments[0]).IsAssignableFrom(valueType))
+                        {
+                            var copyMethod = typeof(ReflectionPropertyDescriptor).GetMethod(nameof(CopyCollection))!.MakeGenericMethod(targetType.GenericTypeArguments[0]);
+                            copyMethod.Invoke(null, new object[] { propertyCurrentValue, value });
+                            return;
+                        }
+                    }
+                }
                 propertyInfo.SetValue(target, value, null);
             }
 
+            public static void CopyCollection<T>(ICollection<T> target, ICollection<T> source)
+            {
+                foreach (var element in source)
+                {
+                    target.Add(element);
+                }
+            }
+
             public T GetCustomAttribute<T>() where T : Attribute
             {
                 var attributes = propertyInfo.GetAllCustomAttributes<T>();