diff --git a/BuildToolsVersion.txt b/BuildToolsVersion.txt
index 7ae3b67f814c..1c965ae32278 100644
--- a/BuildToolsVersion.txt
+++ b/BuildToolsVersion.txt
@@ -1 +1 @@
-3.0.0-preview4-03930-01
+3.0.0-preview4-04022-01
diff --git a/ILAsmVersion.txt b/ILAsmVersion.txt
index 99040410e40d..f24497913329 100644
--- a/ILAsmVersion.txt
+++ b/ILAsmVersion.txt
@@ -1 +1 @@
-3.0.0-preview6-27702-71
+3.0.0-preview6-27721-71
diff --git a/dependencies.props b/dependencies.props
index 795941018505..4d513b821f9b 100644
--- a/dependencies.props
+++ b/dependencies.props
@@ -15,13 +15,13 @@
 
   <!-- Source of truth for dependency tooling: the commit hash of the dotnet/versions master branch as of the last auto-upgrade. -->
   <PropertyGroup>
-    <CoreClrCurrentRef>f1ee12b0dab462d0f58b87e878250146a125d9ff</CoreClrCurrentRef>
-    <BuildToolsCurrentRef>9519ad281b838b0b2bffa86b2837994d4f7c41d3</BuildToolsCurrentRef>
+    <CoreClrCurrentRef>00797464e62272e9c721a1854abe49ff05743bdf</CoreClrCurrentRef>
+    <BuildToolsCurrentRef>00797464e62272e9c721a1854abe49ff05743bdf</BuildToolsCurrentRef>
   </PropertyGroup>
 
   <!-- Tests/infrastructure dependency versions. -->
   <PropertyGroup>
-    <MicrosoftNETCoreRuntimeCoreCLRPackageVersion>3.0.0-preview6-27702-71</MicrosoftNETCoreRuntimeCoreCLRPackageVersion>
+    <MicrosoftNETCoreRuntimeCoreCLRPackageVersion>3.0.0-preview6-27721-71</MicrosoftNETCoreRuntimeCoreCLRPackageVersion>
     <XunitPackageVersion>2.4.1-pre.build.4059</XunitPackageVersion>
     <XunitPerformanceApiPackageVersion>1.0.0-beta-build0015</XunitPerformanceApiPackageVersion>
     <MicrosoftDiagnosticsTracingTraceEventPackageVersion>2.0.40</MicrosoftDiagnosticsTracingTraceEventPackageVersion>
diff --git a/src/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/System.Private.CoreLib/System.Private.CoreLib.csproj
index 9f7b5238f6d7..6ec5b7f5e623 100644
--- a/src/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -56,7 +56,7 @@
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <!-- Remove CS8608 once https://github.com/dotnet/roslyn/issues/23268 is resolved -->
     <NoWarn>649,1573,1591,0419,3021,CS8609</NoWarn>
-    <NullableContextOptions>enable</NullableContextOptions>
+    <Nullable>enable</Nullable>
 
     <!-- Ignore all previous constants since SPCL is sensitive to what is defined and the Sdk adds some by default -->
     <DefineConstants>CORECLR;netcoreapp</DefineConstants>
diff --git a/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems b/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
index 30f15000716c..d7a774bcf84a 100644
--- a/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
+++ b/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
@@ -8,7 +8,7 @@
     <Import_RootNamespace />
   </PropertyGroup>
   <PropertyGroup>
-    <NullableContextOptions>enable</NullableContextOptions>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <PropertyGroup>
     <TargetsWindows Condition="'$(TargetsWindows)' != 'true'">false</TargetsWindows>
diff --git a/src/System.Private.CoreLib/shared/System/Progress.cs b/src/System.Private.CoreLib/shared/System/Progress.cs
index c757da33dc5e..f29849378b11 100644
--- a/src/System.Private.CoreLib/shared/System/Progress.cs
+++ b/src/System.Private.CoreLib/shared/System/Progress.cs
@@ -81,9 +81,9 @@ protected virtual void OnReport(T value)
 
         /// <summary>Invokes the action and event callbacks.</summary>
         /// <param name="state">The progress value.</param>
-        private void InvokeHandlers(object state)
+        private void InvokeHandlers(object? state)
         {
-            T value = (T)state;
+            T value = (T)state!;
 
             Action<T>? handler = _handler;
             EventHandler<T> changedEvent = ProgressChanged;
diff --git a/src/System.Private.CoreLib/shared/System/Threading/Tasks/FutureFactory.cs b/src/System.Private.CoreLib/shared/System/Threading/Tasks/FutureFactory.cs
index b00b623c2734..e8be5bd09121 100644
--- a/src/System.Private.CoreLib/shared/System/Threading/Tasks/FutureFactory.cs
+++ b/src/System.Private.CoreLib/shared/System/Threading/Tasks/FutureFactory.cs
@@ -660,7 +660,7 @@ internal static Task<TResult> FromAsyncImpl(
             // RespectParentCancellation.
             Task t = new Task(new Action<object>(delegate
             {
-                FromAsyncCoreLogic(asyncResult, endFunction, endAction, promise, requiresSynchronization: true);
+                FromAsyncCoreLogic(asyncResult!, endFunction, endAction, promise, requiresSynchronization: true); // TODO-NULLABLE: https://github.com/dotnet/csharplang/issues/538
             }),
                 (object?)null, null,
                 default, TaskCreationOptions.None, InternalTaskOptions.None, null);
diff --git a/src/System.Private.CoreLib/shared/System/Threading/ThreadPool.cs b/src/System.Private.CoreLib/shared/System/Threading/ThreadPool.cs
index da4df11e4f6e..064227bf51b6 100644
--- a/src/System.Private.CoreLib/shared/System/Threading/ThreadPool.cs
+++ b/src/System.Private.CoreLib/shared/System/Threading/ThreadPool.cs
@@ -926,15 +926,15 @@ internal _ThreadPoolWaitOrTimerCallback(WaitOrTimerCallback waitOrTimerCallback,
             }
         }
 
-        private static void WaitOrTimerCallback_Context_t(object state) =>
+        private static void WaitOrTimerCallback_Context_t(object? state) =>
             WaitOrTimerCallback_Context(state, timedOut: true);
 
-        private static void WaitOrTimerCallback_Context_f(object state) =>
+        private static void WaitOrTimerCallback_Context_f(object? state) =>
             WaitOrTimerCallback_Context(state, timedOut: false);
 
-        private static void WaitOrTimerCallback_Context(object state, bool timedOut)
+        private static void WaitOrTimerCallback_Context(object? state, bool timedOut)
         {
-            _ThreadPoolWaitOrTimerCallback helper = (_ThreadPoolWaitOrTimerCallback)state;
+            _ThreadPoolWaitOrTimerCallback helper = (_ThreadPoolWaitOrTimerCallback)state!;
             helper._waitOrTimerCallback(helper._state, timedOut);
         }
 
diff --git a/src/System.Private.CoreLib/src/System/Threading/Overlapped.cs b/src/System.Private.CoreLib/src/System/Threading/Overlapped.cs
index 9bd5cf736f65..e05611e6f023 100644
--- a/src/System.Private.CoreLib/src/System/Threading/Overlapped.cs
+++ b/src/System.Private.CoreLib/src/System/Threading/Overlapped.cs
@@ -43,9 +43,9 @@ internal _IOCompletionCallback(IOCompletionCallback ioCompletionCallback, Execut
         }
         // Context callback: same sig for SendOrPostCallback and ContextCallback
         internal static ContextCallback _ccb = new ContextCallback(IOCompletionCallback_Context);
-        internal static void IOCompletionCallback_Context(object state)
+        internal static void IOCompletionCallback_Context(object? state)
         {
-            _IOCompletionCallback helper = (_IOCompletionCallback)state;
+            _IOCompletionCallback? helper = (_IOCompletionCallback?)state;
             Debug.Assert(helper != null, "_IOCompletionCallback cannot be null");
             helper._ioCompletionCallback(helper._errorCode, helper._numBytes, helper._pNativeOverlapped);
         }
diff --git a/src/System.Private.CoreLib/src/System/Threading/Tasks/AsyncCausalityTracer.cs b/src/System.Private.CoreLib/src/System/Threading/Tasks/AsyncCausalityTracer.cs
index 75d97064bc90..3332f44dbae5 100644
--- a/src/System.Private.CoreLib/src/System/Threading/Tasks/AsyncCausalityTracer.cs
+++ b/src/System.Private.CoreLib/src/System/Threading/Tasks/AsyncCausalityTracer.cs
@@ -81,7 +81,7 @@ static AsyncCausalityTracer()
             }
         }
 
-        private static void TracingStatusChangedHandler(object sender, WFD.TracingStatusChangedEventArgs args)
+        private static void TracingStatusChangedHandler(object? sender, WFD.TracingStatusChangedEventArgs args)
         {
             if (args.Enabled)
                 f_LoggingOn |= Loggers.CausalityTracer;