diff --git a/src/ImageSharp/Memory/ArrayPoolMemoryAllocator.cs b/src/ImageSharp/Memory/ArrayPoolMemoryAllocator.cs
index 90950d4b3..f1c4c49c3 100644
--- a/src/ImageSharp/Memory/ArrayPoolMemoryAllocator.cs
+++ b/src/ImageSharp/Memory/ArrayPoolMemoryAllocator.cs
@@ -9,7 +9,7 @@ namespace SixLabors.Memory
     /// <summary>
     /// Implements <see cref="MemoryAllocator"/> by allocating memory from <see cref="ArrayPool{T}"/>.
     /// </summary>
-    public partial class ArrayPoolMemoryAllocator : MemoryAllocator
+    public sealed partial class ArrayPoolMemoryAllocator : MemoryAllocator
     {
         /// <summary>
         /// The <see cref="ArrayPool{T}"/> for small-to-medium buffers which is not kept clean.
diff --git a/src/ImageSharp/Memory/BasicByteBuffer.cs b/src/ImageSharp/Memory/BasicByteBuffer.cs
index a8a30b1aa..9f995e347 100644
--- a/src/ImageSharp/Memory/BasicByteBuffer.cs
+++ b/src/ImageSharp/Memory/BasicByteBuffer.cs
@@ -3,7 +3,7 @@
 
 namespace SixLabors.Memory
 {
-    internal class BasicByteBuffer : BasicArrayBuffer<byte>, IManagedByteBuffer
+    internal sealed class BasicByteBuffer : BasicArrayBuffer<byte>, IManagedByteBuffer
     {
         internal BasicByteBuffer(byte[] array)
             : base(array)
diff --git a/src/ImageSharp/Memory/Buffer2D{T}.cs b/src/ImageSharp/Memory/Buffer2D{T}.cs
index f8d75b54c..b76c06df8 100644
--- a/src/ImageSharp/Memory/Buffer2D{T}.cs
+++ b/src/ImageSharp/Memory/Buffer2D{T}.cs
@@ -12,7 +12,7 @@ namespace SixLabors.Memory
     /// interpreted as a 2D region of <see cref="Width"/> x <see cref="Height"/> elements.
     /// </summary>
     /// <typeparam name="T">The value type.</typeparam>
-    internal class Buffer2D<T> : IDisposable
+    internal sealed class Buffer2D<T> : IDisposable
         where T : struct
     {
         /// <summary>
diff --git a/src/ImageSharp/Memory/ManagedBufferBase.cs b/src/ImageSharp/Memory/ManagedBufferBase.cs
index 606d1c962..8de2f5392 100644
--- a/src/ImageSharp/Memory/ManagedBufferBase.cs
+++ b/src/ImageSharp/Memory/ManagedBufferBase.cs
@@ -9,7 +9,7 @@ namespace SixLabors.Memory
     /// <summary>
     /// Provides a base class for <see cref="IBuffer{T}"/> implementations by implementing pinning logic for <see cref="MemoryManager{T}"/> adaption.
     /// </summary>
-    internal abstract class ManagedBufferBase<T> : System.Buffers.MemoryManager<T>, IBuffer<T>
+    internal abstract class ManagedBufferBase<T> : MemoryManager<T>, IBuffer<T>
         where T : struct
     {
         private GCHandle pinHandle;
diff --git a/src/ImageSharp/Memory/SimpleGcMemoryAllocator.cs b/src/ImageSharp/Memory/SimpleGcMemoryAllocator.cs
index 2d339f4c7..df69cec6e 100644
--- a/src/ImageSharp/Memory/SimpleGcMemoryAllocator.cs
+++ b/src/ImageSharp/Memory/SimpleGcMemoryAllocator.cs
@@ -3,7 +3,7 @@
     /// <summary>
     /// Implements <see cref="MemoryAllocator"/> by newing up arrays by the GC on every allocation requests.
     /// </summary>
-    public class SimpleGcMemoryAllocator : MemoryAllocator
+    public sealed class SimpleGcMemoryAllocator : MemoryAllocator
     {
         /// <inheritdoc />
         internal override IBuffer<T> Allocate<T>(int length, bool clear)
@@ -16,4 +16,4 @@
             return new BasicByteBuffer(new byte[length]);
         }
     }
-}
+}
\ No newline at end of file