diff --git a/src/Common/src/Interop/Linux/libc/Interop.FcntlCommands.cs b/src/Common/src/Interop/Linux/libc/Interop.FcntlCommands.cs
deleted file mode 100644
index 9c745178fcff..000000000000
--- a/src/Common/src/Interop/Linux/libc/Interop.FcntlCommands.cs
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-internal static partial class Interop
-{
-    internal static partial class libc
-    {
-        internal enum FcntlCommands
-        {
-            F_LINUX_SPECIFIC_BASE = 1024,
-            F_SETPIPE_SZ = F_LINUX_SPECIFIC_BASE + 7,
-            F_GETPIPE_SZ = F_LINUX_SPECIFIC_BASE + 8
-        }
-    }
-}
diff --git a/src/Common/src/Interop/Linux/libc/Interop.pipe2.cs b/src/Common/src/Interop/Linux/libc/Interop.pipe2.cs
deleted file mode 100644
index 957c132c8443..000000000000
--- a/src/Common/src/Interop/Linux/libc/Interop.pipe2.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using System;
-using System.Runtime.InteropServices;
-
-internal static partial class Interop
-{
-    internal static partial class libc
-    {
-        [Flags]
-        internal enum Pipe2Flags
-        {
-            O_CLOEXEC   = 0x80000,
-        }
-
-        [DllImport(Libraries.Libc, SetLastError = true)]
-        internal static extern unsafe int pipe2(int* pipefd, Pipe2Flags flags);
-    }
-}
diff --git a/src/Common/src/Interop/Unix/System.Native/Interop.Fcntl.cs b/src/Common/src/Interop/Unix/System.Native/Interop.Fcntl.cs
new file mode 100644
index 000000000000..7c1782a11cd4
--- /dev/null
+++ b/src/Common/src/Interop/Unix/System.Native/Interop.Fcntl.cs
@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        internal static class Fcntl
+        {
+            internal static readonly bool CanGetSetPipeSz = (FcntlCanGetSetPipeSz() != 0);
+
+            [DllImport(Libraries.SystemNative, EntryPoint="FcntlGetPipeSz", SetLastError=true)]
+            internal static extern int GetPipeSz(int fd);
+
+            [DllImport(Libraries.SystemNative, EntryPoint="FcntlSetPipeSz", SetLastError=true)]
+            internal static extern int SetPipeSz(int fd, int size);
+
+            [DllImport(Libraries.SystemNative)]
+            private static extern int FcntlCanGetSetPipeSz();
+        }
+    }
+}
diff --git a/src/Common/src/Interop/Unix/System.Native/Interop.Pipe.cs b/src/Common/src/Interop/Unix/System.Native/Interop.Pipe.cs
new file mode 100644
index 000000000000..2aabe3736126
--- /dev/null
+++ b/src/Common/src/Interop/Unix/System.Native/Interop.Pipe.cs
@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        [Flags]
+        internal enum PipeFlags
+        {
+            O_CLOEXEC = 0x0010,
+        }
+
+        /// <summary>
+        /// The index into the array filled by <see cref="pipe"/> which represents the read end of the pipe.
+        /// </summary>
+        internal const int ReadEndOfPipe = 0;
+
+        /// <summary>
+        /// The index into the array filled by <see cref="pipe"/> which represents the read end of the pipe.
+        /// </summary>
+        internal const int WriteEndOfPipe = 1;
+
+        [DllImport(Libraries.SystemNative, SetLastError = true)]
+        internal static extern unsafe int Pipe(int* pipefd, PipeFlags flags = 0); // pipefd is an array of two ints
+    }
+}
diff --git a/src/Common/src/Interop/Unix/System.Native/Interop.Stat.cs b/src/Common/src/Interop/Unix/System.Native/Interop.Stat.cs
index 6d76ad10c1b3..2a9ce3d471c3 100644
--- a/src/Common/src/Interop/Unix/System.Native/Interop.Stat.cs
+++ b/src/Common/src/Interop/Unix/System.Native/Interop.Stat.cs
@@ -45,7 +45,7 @@ internal enum FileStatusFlags
         }
 
         [DllImport(Libraries.SystemNative, SetLastError = true)]
-        internal static extern int FStat(int fileDescriptor, out FileStatus output);
+        internal static extern int FStat(int fd, out FileStatus output);
 
         [DllImport(Libraries.SystemNative, SetLastError = true)]
         internal static extern int Stat(string path, out FileStatus output);
diff --git a/src/Common/src/Interop/Unix/System.Native/Interop.readdir.cs b/src/Common/src/Interop/Unix/System.Native/Interop.readdir.cs
index 70ad23588b09..67f1c9d1c8b3 100644
--- a/src/Common/src/Interop/Unix/System.Native/Interop.readdir.cs
+++ b/src/Common/src/Interop/Unix/System.Native/Interop.readdir.cs
@@ -48,7 +48,7 @@ internal struct DirectoryEntry
         private static unsafe extern int ReadDirR(SafeDirectoryHandle dir, byte* buffer, int bufferSize, out InternalDirectoryEntry outputEntry);
 
         [DllImport(Libraries.SystemNative, SetLastError = true)]
-        internal static extern int CloseDir(IntPtr directory);
+        internal static extern int CloseDir(IntPtr dir);
 
         // The calling pattern for ReadDir is described in src/Native/System.Native/pal_readdir.cpp
         internal static int ReadDir(SafeDirectoryHandle dir, out DirectoryEntry outputEntry)
diff --git a/src/Common/src/Interop/Unix/libc/Interop.fcntl.cs b/src/Common/src/Interop/Unix/libc/Interop.fcntl.cs
deleted file mode 100644
index a713a5d89f2d..000000000000
--- a/src/Common/src/Interop/Unix/libc/Interop.fcntl.cs
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using System;
-using System.Runtime.InteropServices;
-
-internal static partial class Interop
-{
-    internal static partial class libc
-    {
-        // fcntl takes a variable number of arguments, which is difficult to represent in C#.
-        // Instead, since we only have a small and fixed number of call sites, we declare
-        // an overload for each of the specific argument sets we need.
-
-        [DllImport(Libraries.Libc)]
-        internal static extern unsafe int fcntl(int fd, FcntlCommands cmd);
-
-        [DllImport(Libraries.Libc)]
-        internal static extern unsafe int fcntl(int fd, FcntlCommands cmd, int arg1);
-    }
-}
diff --git a/src/Common/src/Interop/Unix/libcurl/Interop.SafeCurlHandle.cs b/src/Common/src/Interop/Unix/libcurl/Interop.SafeCurlHandle.cs
index 367058e88d26..3f93f4c189ab 100644
--- a/src/Common/src/Interop/Unix/libcurl/Interop.SafeCurlHandle.cs
+++ b/src/Common/src/Interop/Unix/libcurl/Interop.SafeCurlHandle.cs
@@ -77,7 +77,7 @@ public SafeCurlMultiHandle()
                 {
                     fixed(int* fds = _specialFds)
                     {
-                        while (Interop.CheckIo(libc.pipe(fds)));
+                        while (Interop.CheckIo(Interop.Sys.Pipe(fds)));
                     }
                 }
             }
@@ -116,7 +116,7 @@ internal void PollFds(List<libc.pollfd> readyFds)
                     // is ready for a read/write. The special fd is the read end of a pipe
                     // Whenever an fd is added/removed in _fdSet, a write happens to the
                     // write end of the pipe thus causing the poll to return.
-                    pollFds[0].fd = _specialFds[libc.ReadEndOfPipe];
+                    pollFds[0].fd = _specialFds[Interop.Sys.ReadEndOfPipe];
                     pollFds[0].events = PollFlags.POLLIN;
                     int i = 1;
                     foreach (int fd in _fdSet)
@@ -186,7 +186,7 @@ internal void SignalFdSetChange(int fd, bool isRemove)
                 {
                     // Write to special fd
                     byte* dummyBytes = stackalloc byte[1];
-                    if ((int)libc.write(_specialFds[libc.WriteEndOfPipe], dummyBytes, (size_t)1) <= 0)
+                    if ((int)libc.write(_specialFds[Interop.Sys.WriteEndOfPipe], dummyBytes, (size_t)1) <= 0)
                     {
                         // TODO: How to handle errors?
                         throw new InvalidOperationException("Cannot write data: " + Marshal.GetLastWin32Error());
@@ -212,8 +212,8 @@ protected override bool ReleaseHandle()
                 Debug.Assert(0 == _requestCount);
                 Debug.Assert(_pollCancelled);
 
-                Interop.Sys.Close(_specialFds[libc.ReadEndOfPipe]);
-                Interop.Sys.Close(_specialFds[libc.WriteEndOfPipe]);
+                Interop.Sys.Close(_specialFds[Interop.Sys.ReadEndOfPipe]);
+                Interop.Sys.Close(_specialFds[Interop.Sys.WriteEndOfPipe]);
                 libcurl.curl_multi_cleanup(this.handle);
 
                 return true;
@@ -227,7 +227,7 @@ private int ReadSpecialFd(PollFlags revents)
                     return -1;
                 }
                 Debug.Assert((revents & PollFlags.POLLIN) != 0);
-                int pipeReadFd = _specialFds[libc.ReadEndOfPipe];
+                int pipeReadFd = _specialFds[Interop.Sys.ReadEndOfPipe];
                 int bytesRead = 0;
                 unsafe
                 {
diff --git a/src/Native/System.Native/pal_io.cpp b/src/Native/System.Native/pal_io.cpp
index 0b302b6119cf..1707b0cc5d43 100644
--- a/src/Native/System.Native/pal_io.cpp
+++ b/src/Native/System.Native/pal_io.cpp
@@ -97,10 +97,10 @@ int32_t Stat(const char* path, FileStatus* output)
 }
 
 extern "C"
-int32_t FStat(int32_t fileDescriptor, FileStatus* output)
+int32_t FStat(int32_t fd, FileStatus* output)
 {
     struct stat_ result;
-    int ret = fstat_(fileDescriptor, &result);
+    int ret = fstat_(fd, &result);
 
     if (ret == 0)
     {
@@ -185,9 +185,9 @@ int32_t Open(const char* path, int32_t flags, int32_t mode)
 }
 
 extern "C"
-int32_t Close(int32_t fileDescriptor)
+int32_t Close(int32_t fd)
 {
-    return close(fileDescriptor);
+    return close(fd);
 }
 
 extern "C"
@@ -215,7 +215,6 @@ int32_t ShmUnlink(const char* name)
     return shm_unlink(name);
 }
 
-
 static
 void ConvertDirent(const dirent& entry, DirectoryEntry* outputEntry)
 {
@@ -299,7 +298,62 @@ DIR* OpenDir(const char* path)
 }
 
 extern "C" 
-int32_t CloseDir(DIR* directory)
+int32_t CloseDir(DIR* dir)
+{
+    return closedir(dir);
+}
+
+extern "C"
+int32_t Pipe(int32_t pipeFds[2], int32_t flags)
 {
-    return closedir(directory);
+    switch (flags)
+    {
+    case 0:
+        break;
+    case PAL_O_CLOEXEC:
+        flags = O_CLOEXEC;
+        break;
+    default:
+        assert(!"Unknown flag.");
+        errno = EINVAL;
+        return -1;
+    }
+
+#if HAVE_PIPE2
+    return pipe2(pipeFds, flags);
+#else
+    return pipe(pipeFds); // CLOEXEC intentionally ignored on platforms without pipe2.
+#endif
+}
+
+extern "C"
+int32_t FcntlCanGetSetPipeSz()
+{
+#if defined(F_GETPIPE_SZ) && defined(F_SETPIPE_SZ)
+    return true;
+#else
+    return false;
+#endif
+}
+
+extern "C"
+int32_t FcntlGetPipeSz(int32_t fd)
+{
+#ifdef F_GETPIPE_SZ
+    return fcntl(fd, F_GETPIPE_SZ);
+#else
+    errno = ENOTSUP;
+    return -1;
+#endif
+}
+
+extern "C"
+int32_t FcntlSetPipeSz(int32_t fd, int32_t size)
+{
+#ifdef F_SETPIPE_SZ
+    return fcntl(fd, F_SETPIPE_SZ, size);
+#else
+    errno = ENOTSUP;
+    return -1;
+#endif
 }
diff --git a/src/Native/System.Native/pal_io.h b/src/Native/System.Native/pal_io.h
index 547b2bfbf1a1..2929c0e459f6 100644
--- a/src/Native/System.Native/pal_io.h
+++ b/src/Native/System.Native/pal_io.h
@@ -129,7 +129,7 @@ struct DirectoryEntry
  */
 extern "C"
 int32_t FStat(
-    int32_t fileDescriptor,
+    int32_t fd,
     FileStatus* output);
 
 /**
@@ -160,7 +160,7 @@ int32_t LStat(
 extern "C"
 int32_t Open(
     const char* path,
-    int32_t oflag,
+    int32_t flags,
     int32_t mode);
 
 /**
@@ -170,8 +170,8 @@ int32_t Open(
  */
 extern "C"
 int32_t Close(
-    int32_t fileDescriptor);
-    
+    int32_t fd);
+
 /**
  * Delete an entry from the file system. Implemented as shim to unlink(2).
  *
@@ -180,7 +180,7 @@ int32_t Close(
 extern "C"
 int32_t Unlink(
     const char* path);
-    
+
 /**
  * Open or create a shared memory object. Implemented as shim to shm_open(3).
  *
@@ -188,9 +188,9 @@ int32_t Unlink(
  */
 extern "C"
 int32_t ShmOpen(
-     const char* name,
-     int32_t oflag,
-     int32_t mode);
+    const char* name,
+    int32_t flags,
+    int32_t mode);
      
 /**
  * Unlink a shared memory object. Implemented as shim to shm_unlink(3).
@@ -223,10 +223,59 @@ int32_t ReadDirR(
  * Returns a DIR struct containing info about the current path or NULL on failure; sets errno on fail.
  */
 extern "C"
-DIR* OpenDir(const char* path);
+DIR* OpenDir(
+    const char* path);
 
 /**
  * Closes the directory stream opened by opendir and returns 0 on success. On fail, -1 is returned and errno is set
  */
 extern "C"
-int32_t CloseDir(DIR* directory);
\ No newline at end of file
+int32_t CloseDir(
+    DIR* dir);
+
+/**
+ * Creates a pipe. Implemented as shim to pipe(2) or pipe2(2) if available.
+ * Flags are ignored if pipe2 is not available.
+ *
+ * Returns 0 for success, -1 for failure. Sets errno on failure.
+ */
+extern "C"
+int32_t Pipe(
+    int32_t pipefd[2], // [out] pipefds[0] gets read end, pipefd[1] gets write end.
+    int32_t flags);    // 0 for defaults or PAL_O_CLOEXEC for close-on-exec
+
+
+// NOTE: Rather than a general fcntl shim, we opt to export separate functions 
+// for each command. This allows use to have strongly typed arguments and saves
+// complexity around converting command codes.
+
+/**
+ * Determines if the current platform supports getting and setting pipe capacity.
+ *
+ * Returns true (non-zero) if supported, false (zero) if not.
+ */
+extern "C"
+int32_t FcntlCanGetSetPipeSz();
+
+/**
+ * Gets the capacity of a pipe.
+ *
+ * Returns the capacity or -1 with errno set aprropriately on failure.
+ *
+ * NOTE: Some platforms do not support this operation and will always fail with errno = ENOTSUP.
+ */
+extern "C"
+int32_t FcntlGetPipeSz(
+    int32_t fd);
+
+/**
+ * Sets the capacity of a pipe.
+ *
+ * Returns 0 for success, -1 for failure. Sets errno for failure.
+ *
+ * NOTE: Some platforms do not support this operation and will always fail with errno = ENOTSUP.
+ */
+extern "C"
+int32_t FcntlSetPipeSz(
+    int32_t fd,
+    int32_t size);
\ No newline at end of file
diff --git a/src/Native/config.h.in b/src/Native/config.h.in
index 9f7e0ac1bf47..ca932191c406 100644
--- a/src/Native/config.h.in
+++ b/src/Native/config.h.in
@@ -1,6 +1,7 @@
 #pragma once
 
 #cmakedefine01 HAVE_STAT64
+#cmakedefine01 HAVE_PIPE2
 #cmakedefine01 HAVE_STAT_BIRTHTIME
 #cmakedefine01 HAVE_GNU_STRERROR_R
 #cmakedefine01 HAVE_DIRENT_NAME_LEN
diff --git a/src/Native/configure.cmake b/src/Native/configure.cmake
index e8c39dd90b73..a1b228be4732 100644
--- a/src/Native/configure.cmake
+++ b/src/Native/configure.cmake
@@ -6,6 +6,10 @@ check_function_exists(
     stat64
     HAVE_STAT64)
 
+check_function_exists(
+    pipe2
+    HAVE_PIPE2)
+
 check_struct_has_member(
     "struct stat"
     st_birthtime
diff --git a/src/System.IO.Pipes/src/System.IO.Pipes.csproj b/src/System.IO.Pipes/src/System.IO.Pipes.csproj
index d61fdb582ffa..51d614f6af33 100644
--- a/src/System.IO.Pipes/src/System.IO.Pipes.csproj
+++ b/src/System.IO.Pipes/src/System.IO.Pipes.csproj
@@ -153,12 +153,12 @@
     <Compile Include="$(CommonPath)\Interop\Unix\Interop.IOErrors.cs">
       <Link>Common\Interop\Unix\Interop.IOErrors.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)\Interop\Linux\libc\Interop.pipe2.cs">
-      <Link>Common\Interop\Unix\Interop.pipe2.cs</Link>
-    </Compile>
     <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Close.cs">
       <Link>Common\Interop\Unix\Interop.Close.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Fcntl.cs">
+      <Link>Common\Interop\Unix\Interop.Fcntl.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.gethostname.cs">
       <Link>Common\Interop\Unix\Interop.gethostname.cs</Link>
     </Compile>
@@ -180,8 +180,8 @@
     <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.Permissions.cs">
       <Link>Common\Interop\Unix\Interop.Permissions.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.pipe.cs">
-      <Link>Common\Interop\Unix\Interop.pipe.cs</Link>
+    <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Pipe.cs">
+      <Link>Common\Interop\Unix\Interop.Pipe.cs</Link>
     </Compile>
     <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.poll.cs">
       <Link>Common\Interop\Unix\Interop.poll.cs</Link>
@@ -205,20 +205,6 @@
       <Link>Common\System\Threading\Tasks\ForceAsyncAwaiter.cs</Link>
     </Compile>
   </ItemGroup>
-  <!-- Linux -->
-  <ItemGroup Condition="'$(TargetsLinux)' == 'true'">
-    <Compile Include="System\IO\Pipes\PipeStream.Linux.cs" />
-    <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.fcntl.cs">
-      <Link>Common\Interop\Unix\Interop.fcntl.cs</Link>
-    </Compile>
-    <Compile Include="$(CommonPath)\Interop\Linux\libc\Interop.FcntlCommands.cs">
-      <Link>Common\Interop\Linux\Interop.FcntlCommands.cs</Link>
-    </Compile>
-  </ItemGroup>
-  <!-- OSX -->
-  <ItemGroup Condition="'$(TargetsOSX)' == 'true'">
-    <Compile Include="System\IO\Pipes\PipeStream.OSX.cs" />
-  </ItemGroup>
   <!-- Resource files -->
   <ItemGroup>
     <None Include="project.json" />
diff --git a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Linux.cs b/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Linux.cs
deleted file mode 100644
index f0bcc8e4993f..000000000000
--- a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Linux.cs
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using Microsoft.Win32.SafeHandles;
-
-namespace System.IO.Pipes
-{
-    public abstract partial class PipeStream
-    {
-        internal void InitializeBufferSize(SafePipeHandle handle, int bufferSize)
-        {
-            if (bufferSize > 0)
-            {
-                SysCall(handle, (fd, _, size, __) => Interop.libc.fcntl(fd, Interop.libc.FcntlCommands.F_SETPIPE_SZ, size), 
-                    IntPtr.Zero, bufferSize);
-            }
-        }
-
-        private int InBufferSizeCore { get { return GetPipeBufferSize(); } }
-
-        private int OutBufferSizeCore { get { return GetPipeBufferSize(); } }
-
-        private int GetPipeBufferSize()
-        {
-            // If we have a handle, get the capacity of the pipe (there's no distinction between in/out direction).
-            // If we don't, the pipe has been created but not yet connected (in the case of named pipes),
-            // so just return the buffer size that was passed to the constructor.
-            return _handle != null ?
-                (int)SysCall(_handle, (fd, _, __, ___) => Interop.libc.fcntl(fd, Interop.libc.FcntlCommands.F_GETPIPE_SZ)) :
-                _outBufferSize;
-        }
-
-        internal static unsafe void CreateAnonymousPipe(HandleInheritability inheritability, int* fdsptr)
-        {
-            var flags = (inheritability & HandleInheritability.Inheritable) == 0 ?
-                Interop.libc.Pipe2Flags.O_CLOEXEC : 0;
-            while (Interop.CheckIo(Interop.libc.pipe2(fdsptr, flags))) ;
-        }
-    }
-}
diff --git a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.OSX.cs b/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.OSX.cs
deleted file mode 100644
index fc3234ffbc0a..000000000000
--- a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.OSX.cs
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using Microsoft.Win32.SafeHandles;
-
-namespace System.IO.Pipes
-{
-    public abstract partial class PipeStream
-    {
-        internal void InitializeBufferSize(SafePipeHandle handle, int bufferSize)
-        {
-            // Nop.  We can't configure the capacity, and as it's just advisory, ignore it.
-        }
-
-        private int InBufferSizeCore { get { throw new PlatformNotSupportedException(); } }
-
-        private int OutBufferSizeCore { get { throw new PlatformNotSupportedException(); } }
-
-        internal static unsafe void CreateAnonymousPipe(HandleInheritability inheritability, int* fdsptr)
-        {
-            // Ignore inheritability, as on OSX pipe2 isn't available
-            while (Interop.CheckIo(Interop.libc.pipe(fdsptr))) ;
-        }
-    }
-}
diff --git a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Unix.cs b/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Unix.cs
index 99609bbbb01c..778314651d6b 100644
--- a/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Unix.cs
+++ b/src/System.IO.Pipes/src/System/IO/Pipes/PipeStream.Unix.cs
@@ -154,7 +154,7 @@ public virtual int InBufferSize
                 {
                     throw new NotSupportedException(SR.NotSupported_UnreadableStream);
                 }
-                return InBufferSizeCore;
+                return GetPipeBufferSize();
             }
         }
 
@@ -173,7 +173,7 @@ public virtual int OutBufferSize
                 {
                     throw new NotSupportedException(SR.NotSupported_UnwritableStream);
                 }
-                return OutBufferSizeCore;
+                return GetPipeBufferSize();
             }
         }
 
@@ -452,8 +452,8 @@ internal static unsafe void CreateAnonymousPipe(
             CreateAnonymousPipe(inheritability, fds);
 
             // Store the file descriptors into our safe handles
-            reader.SetHandle(fds[Interop.libc.ReadEndOfPipe]);
-            writer.SetHandle(fds[Interop.libc.WriteEndOfPipe]);
+            reader.SetHandle(fds[Interop.Sys.ReadEndOfPipe]);
+            writer.SetHandle(fds[Interop.Sys.WriteEndOfPipe]);
         }
 
         /// <summary>
@@ -588,5 +588,36 @@ private long SysCall(
             }
         }
 
+        internal void InitializeBufferSize(SafePipeHandle handle, int bufferSize)
+        {
+            // bufferSize is just advisory and ignored if platform does not support setting pipe capacity via fcntl.
+            if (bufferSize > 0 && Interop.Sys.Fcntl.CanGetSetPipeSz)
+            {
+                SysCall(handle, (fd, _, size, __) => Interop.Sys.Fcntl.SetPipeSz(fd, size), 
+                    IntPtr.Zero, bufferSize);
+            }
+        }
+
+        private int GetPipeBufferSize()
+        {
+            if (!Interop.Sys.Fcntl.CanGetSetPipeSz)
+            {
+                throw new PlatformNotSupportedException();
+            }
+
+            // If we have a handle, get the capacity of the pipe (there's no distinction between in/out direction).
+            // If we don't, the pipe has been created but not yet connected (in the case of named pipes),
+            // so just return the buffer size that was passed to the constructor.
+            return _handle != null ?
+                (int)SysCall(_handle, (fd, _, __, ___) => Interop.Sys.Fcntl.GetPipeSz(fd)) :
+                _outBufferSize;
+        }
+
+        internal static unsafe void CreateAnonymousPipe(HandleInheritability inheritability, int* fdsptr)
+        {
+            var flags = (inheritability & HandleInheritability.Inheritable) == 0 ?
+                Interop.Sys.PipeFlags.O_CLOEXEC : 0;
+            while (Interop.CheckIo(Interop.Sys.Pipe(fdsptr, flags))) ;
+        }
     }
 }
diff --git a/src/System.Net.Http/src/System.Net.Http.csproj b/src/System.Net.Http/src/System.Net.Http.csproj
index 226d18da6957..8e14f3b0c560 100644
--- a/src/System.Net.Http/src/System.Net.Http.csproj
+++ b/src/System.Net.Http/src/System.Net.Http.csproj
@@ -159,8 +159,8 @@
     <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.OpenFlags.cs">
       <Link>Common\Interop\Unix\System.Native\Interop.OpenFlags.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.pipe.cs">
-      <Link>Common\Interop\Unix\libc\Interop.pipe.cs</Link>
+    <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Pipe.cs">
+      <Link>Common\Interop\Unix\System.Native\Interop.Pipe.cs</Link>
     </Compile>
     <Compile Include="$(CommonPath)\Interop\Unix\libc\Interop.poll.cs">
       <Link>Common\Interop\Unix\libc\Interop.poll.cs</Link>