diff --git a/CHANGELOG.md b/CHANGELOG.md
index a9c625df..4d98a072 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@ All notable changes to NetVips will be documented in this file. See [here](CHANG
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.4.1] - ???
+### Fixed
+- Avoid key collision during shared `VOption` merge.
+
 ## [2.4.0] - 2023-11-12
 ### Changed
 - Update methods/enums for libvips 8.15.
@@ -219,6 +223,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
 - First release!
 
+[2.4.1]: https://github.com/kleisauke/net-vips/compare/v2.4.0...v2.4.1
 [2.4.0]: https://github.com/kleisauke/net-vips/compare/v2.3.1...v2.4.0
 [2.3.1]: https://github.com/kleisauke/net-vips/compare/v2.3.0...v2.3.1
 [2.3.0]: https://github.com/kleisauke/net-vips/compare/v2.2.0...v2.3.0
diff --git a/src/NetVips/VOption.cs b/src/NetVips/VOption.cs
index 6b01a8bc..8f963ec5 100644
--- a/src/NetVips/VOption.cs
+++ b/src/NetVips/VOption.cs
@@ -29,7 +29,7 @@ public class VOption : IEnumerable<KeyValuePair<string, object>>
         public object this[string key]
         {
             get => _internalDictionary[key];
-            set => Add(key, value);
+            set => _internalDictionary[key] = value;
         }
 
         /// <summary>