diff --git a/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
index 052f8cf6c2a6e2..25176927fd9997 100644
--- a/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -20,7 +20,6 @@
     <ILLinkDirectory>$(MSBuildThisFileDirectory)src\ILLink\</ILLinkDirectory>
 
     <FeaturePortableThreadPool>true</FeaturePortableThreadPool>
-    <FeatureSharedLowLevelLock>true</FeatureSharedLowLevelLock>
   </PropertyGroup>
 
   <!-- Note that various places in SPCL depend on this resource name i.e. TplEventSource -->
diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index bc84b8c6174d77..54b28564911c76 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -978,7 +978,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LazyInitializer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LazyThreadSafetyMode.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LockRecursionException.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LowLevelLock.cs" Condition="'$(FeatureSharedLowLevelLock)' == 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LowLevelLock.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LowLevelSpinWaiter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\LowLevelMonitor.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Threading\ManualResetEvent.cs" />
diff --git a/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
index ddbe6612a4663c..fcb64a0ae6947b 100644
--- a/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -254,7 +254,6 @@
       <Compile Include="$(BclSourcesRoot)\System\Threading\PreAllocatedOverlapped.cs" />
       <Compile Include="$(BclSourcesRoot)\System\Threading\Thread.Mono.cs" />
       <Compile Include="$(BclSourcesRoot)\System\Threading\ThreadPool.Mono.cs" />
-      <Compile Include="$(BclSourcesRoot)\System\Threading\LowLevelLock.cs" />
       <Compile Include="$(BclSourcesRoot)\System\Threading\WaitHandle.Mono.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
diff --git a/src/mono/System.Private.CoreLib/src/System/Threading/LowLevelLock.cs b/src/mono/System.Private.CoreLib/src/System/Threading/LowLevelLock.cs
deleted file mode 100644
index 84b740b63ee9a6..00000000000000
--- a/src/mono/System.Private.CoreLib/src/System/Threading/LowLevelLock.cs
+++ /dev/null
@@ -1,40 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-using System.Diagnostics;
-
-namespace System.Threading
-{
-    // This class provides implementation of uninterruptible lock for internal
-    // use by thread pool.
-    internal class LowLevelLock : IDisposable
-    {
-        public void Dispose()
-        {
-        }
-
-        public bool TryAcquire()
-        {
-            bool lockTaken = false;
-            Monitor.try_enter_with_atomic_var(this, 0, false, ref lockTaken);
-            return lockTaken;
-        }
-
-        public void Acquire()
-        {
-            bool lockTaken = false;
-            Monitor.try_enter_with_atomic_var(this, Timeout.Infinite, false, ref lockTaken);
-        }
-
-        public void Release()
-        {
-            Monitor.Exit(this);
-        }
-
-        [Conditional("DEBUG")]
-        public void VerifyIsLocked()
-        {
-            Debug.Assert(Monitor.IsEntered(this));
-        }
-    }
-}