diff --git a/src/libraries/System.IO.Pipelines/src/System.IO.Pipelines.csproj b/src/libraries/System.IO.Pipelines/src/System.IO.Pipelines.csproj
index ec9632c4d1f25..9e3f41ee8236a 100644
--- a/src/libraries/System.IO.Pipelines/src/System.IO.Pipelines.csproj
+++ b/src/libraries/System.IO.Pipelines/src/System.IO.Pipelines.csproj
@@ -9,7 +9,8 @@ Commonly Used Types:
 System.IO.Pipelines.Pipe
 System.IO.Pipelines.PipeWriter
 System.IO.Pipelines.PipeReader</PackageDescription>
-    <ServicingVersion>2</ServicingVersion>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <ServicingVersion>3</ServicingVersion>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(CommonPath)System\Threading\Tasks\TaskToApm.cs"
diff --git a/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs b/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
index d9b0b8c7a99eb..0c743f4c74a67 100644
--- a/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
+++ b/src/libraries/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
@@ -347,7 +347,7 @@ internal ValueTask<FlushResult> FlushAsync(CancellationToken cancellationToken)
             ValueTask<FlushResult> result;
             lock (SyncObj)
             {
-                PrepareFlush(out completionData, out result, cancellationToken);
+                PrepareFlushUnsynchronized(out completionData, out result, cancellationToken);
             }
 
             TrySchedule(ReaderScheduler, completionData);
@@ -355,7 +355,7 @@ internal ValueTask<FlushResult> FlushAsync(CancellationToken cancellationToken)
             return result;
         }
 
-        private void PrepareFlush(out CompletionData completionData, out ValueTask<FlushResult> result, CancellationToken cancellationToken)
+        private void PrepareFlushUnsynchronized(out CompletionData completionData, out ValueTask<FlushResult> result, CancellationToken cancellationToken)
         {
             var completeReader = CommitUnsynchronized();
 
@@ -691,6 +691,9 @@ internal ValueTask<ReadResult> ReadAtLeastAsync(int minimumBytes, CancellationTo
 
                     // We also need to flip the reading state off
                     _operationState.EndRead();
+
+                    // Begin read again to wire up cancellation token
+                    _readerAwaitable.BeginOperation(token, s_signalReaderAwaitable, this);
                 }
 
                 // If the writer is currently paused and we are about the wait for more data then this would deadlock.
@@ -1057,7 +1060,7 @@ internal ValueTask<FlushResult> WriteAsync(ReadOnlyMemory<byte> source, Cancella
                     WriteMultiSegment(source.Span);
                 }
 
-                PrepareFlush(out completionData, out result, cancellationToken);
+                PrepareFlushUnsynchronized(out completionData, out result, cancellationToken);
             }
 
             TrySchedule(ReaderScheduler, completionData);
diff --git a/src/libraries/System.IO.Pipelines/tests/PipeReaderReadAtLeastAsyncTests.cs b/src/libraries/System.IO.Pipelines/tests/PipeReaderReadAtLeastAsyncTests.cs
index c12d3b88253cf..64762de5ec8ce 100644
--- a/src/libraries/System.IO.Pipelines/tests/PipeReaderReadAtLeastAsyncTests.cs
+++ b/src/libraries/System.IO.Pipelines/tests/PipeReaderReadAtLeastAsyncTests.cs
@@ -162,5 +162,36 @@ public async Task WriteAndCancellingPendingReadBeforeReadAtLeastAsync()
             Assert.True(result.IsCanceled);
             PipeReader.AdvanceTo(buffer.End);
         }
+
+        [Fact]
+        public Task ReadAtLeastAsyncCancelableWhenWaitingForMoreData()
+        {
+            CancellationTokenSource cts = new CancellationTokenSource();
+            ValueTask<ReadResult> task = PipeReader.ReadAtLeastAsync(1, cts.Token);
+            cts.Cancel();
+            return Assert.ThrowsAsync<OperationCanceledException>(async () => await task);
+        }
+
+        [Fact]
+        public async Task ReadAtLeastAsyncCancelableAfterReadingSome()
+        {
+            CancellationTokenSource cts = new CancellationTokenSource();
+            await Pipe.WriteAsync(new byte[10], default);
+            ValueTask<ReadResult> task = PipeReader.ReadAtLeastAsync(11, cts.Token);
+            cts.Cancel();
+            await Assert.ThrowsAsync<OperationCanceledException>(async () => await task);
+        }
+
+        [Fact]
+        public async Task ReadAtLeastAsyncCancelableAfterReadingSomeAndWritingAfterStartingRead()
+        {
+            CancellationTokenSource cts = new CancellationTokenSource();
+            await Pipe.WriteAsync(new byte[10], default);
+            ValueTask<ReadResult> task = PipeReader.ReadAtLeastAsync(12, cts.Token);
+            // Write, but not enough to unblock ReadAtLeastAsync
+            await Pipe.WriteAsync(new byte[1], default);
+            cts.Cancel();
+            await Assert.ThrowsAnyAsync<OperationCanceledException>(async () => await task);
+        }
     }
 }
diff --git a/src/libraries/System.Text.Json/src/System.Text.Json.csproj b/src/libraries/System.Text.Json/src/System.Text.Json.csproj
index d88d2be69fefd..3ee7607c9b11b 100644
--- a/src/libraries/System.Text.Json/src/System.Text.Json.csproj
+++ b/src/libraries/System.Text.Json/src/System.Text.Json.csproj
@@ -9,7 +9,8 @@
     <Nullable>enable</Nullable>
     <IncludeInternalObsoleteAttribute>true</IncludeInternalObsoleteAttribute>
     <IsPackable>true</IsPackable>
-    <ServicingVersion>3</ServicingVersion>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <ServicingVersion>4</ServicingVersion>
     <PackageDescription>Provides high-performance and low-allocating types that serialize objects to JavaScript Object Notation (JSON) text and deserialize JSON text to objects, with UTF-8 support built-in. Also provides types to read and write JSON text encoded as UTF-8, and to create an in-memory document object model (DOM), that is read-only, for random access of the JSON elements within a structured view of the data.
 
 Commonly Used Types:
diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs
index 77b5d7071f712..2563794dcc55c 100644
--- a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs
+++ b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs
@@ -10,6 +10,7 @@
 using System.Text.Json.Serialization;
 using System.Text.Json.Serialization.Converters;
 using System.Text.Json.Serialization.Metadata;
+using System.Threading;
 
 namespace System.Text.Json
 {
@@ -30,10 +31,10 @@ public sealed partial class JsonSerializerOptions
         [RequiresUnreferencedCode(JsonSerializer.SerializationUnreferencedCodeMessage)]
         private void RootBuiltInConverters()
         {
-            if (s_defaultSimpleConverters is null)
+            if (Volatile.Read(ref s_defaultFactoryConverters) is null)
             {
                 s_defaultSimpleConverters = GetDefaultSimpleConverters();
-                s_defaultFactoryConverters = new JsonConverter[]
+                Volatile.Write(ref s_defaultFactoryConverters, new JsonConverter[]
                 {
                     // Check for disallowed types.
                     new UnsupportedTypeConverterFactory(),
@@ -48,7 +49,7 @@ private void RootBuiltInConverters()
                     new IEnumerableConverterFactory(),
                     // Object should always be last since it converts any type.
                     new ObjectConverterFactory()
-                };
+                });
             }
         }