diff --git a/Xledger.Collections.Test/TestMemoryOwner.cs b/Xledger.Collections.Test/TestMemoryOwner.cs
index 3ec256c..c3ea828 100644
--- a/Xledger.Collections.Test/TestMemoryOwner.cs
+++ b/Xledger.Collections.Test/TestMemoryOwner.cs
@@ -1,4 +1,6 @@
 using System.Buffers;
+using System.IO;
+using System.Threading.Tasks;
 using Xledger.Collections.Memory;
 
 namespace Xledger.Collections.Test;
@@ -20,4 +22,22 @@ public void TestSlice() {
         IMemoryOwner<byte> sliced2 = sliced.Slice(1, 4);
         Assert.Equal(array.AsMemory().Slice(3).Slice(1, 4), sliced2.Memory);
     }
+
+#if NET
+    [Fact]
+    public void TestStream_ToMemoryOwner() {
+        byte[] array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+        var ms = new MemoryStream(array);
+        using var memoryOwner = ms.ToOwnedMemory();
+        Assert.Equal(array.AsMemory(), memoryOwner.Memory);
+    }
+
+    [Fact]
+    public async Task TestStream_ToMemoryOwnerAsync() {
+        byte[] array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+        var ms = new MemoryStream(array);
+        using var memoryOwner = await ms.ToOwnedMemoryAsync();
+        Assert.Equal(array.AsMemory(), memoryOwner.Memory);
+    }
+#endif
 }
diff --git a/Xledger.Collections.Test/Xledger.Collections.Test.csproj b/Xledger.Collections.Test/Xledger.Collections.Test.csproj
index 649b7be..7ef5883 100644
--- a/Xledger.Collections.Test/Xledger.Collections.Test.csproj
+++ b/Xledger.Collections.Test/Xledger.Collections.Test.csproj
@@ -23,8 +23,8 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
-    <PackageReference Include="xunit" Version="2.4.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
diff --git a/Xledger.Collections/Memory/Extensions.cs b/Xledger.Collections/Memory/Extensions.cs
index 0c32be5..a196b4d 100644
--- a/Xledger.Collections/Memory/Extensions.cs
+++ b/Xledger.Collections/Memory/Extensions.cs
@@ -38,9 +38,7 @@ public static IMemoryOwner<byte> ToOwnedMemory(this Stream source, bool leaveOpe
 
         try {
             while (true) {
-                var dest = currentBuffer.Slice(totalBytesRead);
-
-                int bytesRead = source.Read(dest.Span);
+                int bytesRead = source.Read(currentBuffer.Span);
 
                 if (bytesRead == 0) {
                     break;
@@ -68,7 +66,7 @@ public static IMemoryOwner<byte> ToOwnedMemory(this Stream source, bool leaveOpe
                 var newOwner = MemoryPool<byte>.Shared.Rent((int)newCapacity);
                 var newBuffer = newOwner.Memory;
 
-                currentBuffer.Slice(0, totalBytesRead).CopyTo(newBuffer);
+                currentBuffer.CopyTo(newBuffer);
                 currentOwner.Dispose();
                 currentOwner = newOwner;
                 currentBuffer = newBuffer;
@@ -82,7 +80,7 @@ public static IMemoryOwner<byte> ToOwnedMemory(this Stream source, bool leaveOpe
             }
         }
 
-        return currentOwner.Slice(totalBytesRead);
+        return currentOwner.Slice(0, totalBytesRead);
     }
 
     static readonly byte[] ASYNC_PROBE = new byte[1];
@@ -102,9 +100,7 @@ public static async Task<IMemoryOwner<byte>> ToOwnedMemoryAsync(this Stream sour
             while (true) {
                 tok.ThrowIfCancellationRequested();
 
-                var dest = currentBuffer.Slice(totalBytesRead);
-
-                int bytesRead = await source.ReadAsync(dest, tok).ConfigureAwait(false);
+                int bytesRead = await source.ReadAsync(currentBuffer, tok).ConfigureAwait(false);
 
                 if (bytesRead == 0) {
                     break;
@@ -131,7 +127,7 @@ public static async Task<IMemoryOwner<byte>> ToOwnedMemoryAsync(this Stream sour
                 var newOwner = MemoryPool<byte>.Shared.Rent((int)newCapacity);
                 var newBuffer = newOwner.Memory;
 
-                currentBuffer.Slice(0, totalBytesRead).CopyTo(newBuffer);
+                currentBuffer.CopyTo(newBuffer);
                 currentOwner.Dispose();
                 currentOwner = newOwner;
                 currentBuffer = newBuffer;
@@ -145,7 +141,7 @@ public static async Task<IMemoryOwner<byte>> ToOwnedMemoryAsync(this Stream sour
             }
         }
 
-        return currentOwner.Slice(totalBytesRead);
+        return currentOwner.Slice(0, totalBytesRead);
     }
 
     // Copied from System.IO.Stream, adapted to be static