diff --git a/src/Connections.Abstractions/DuplexPipe.cs b/src/Kestrel.Core/Internal/DuplexPipe.cs
similarity index 96%
rename from src/Connections.Abstractions/DuplexPipe.cs
rename to src/Kestrel.Core/Internal/DuplexPipe.cs
index e7a6ad1710..adc18c8c7d 100644
--- a/src/Connections.Abstractions/DuplexPipe.cs
+++ b/src/Kestrel.Core/Internal/DuplexPipe.cs
@@ -2,7 +2,7 @@
 
 namespace System.IO.Pipelines
 {
-    public class DuplexPipe : IDuplexPipe
+    internal class DuplexPipe : IDuplexPipe
     {
         public DuplexPipe(PipeReader reader, PipeWriter writer)
         {