diff --git a/src/Microsoft.AspNetCore.Http/Internal/ReferenceReadStream.cs b/src/Microsoft.AspNetCore.Http/Internal/ReferenceReadStream.cs
index be51a2f487..8a8c1e95de 100644
--- a/src/Microsoft.AspNetCore.Http/Internal/ReferenceReadStream.cs
+++ b/src/Microsoft.AspNetCore.Http/Internal/ReferenceReadStream.cs
@@ -139,19 +139,28 @@ namespace Microsoft.AspNetCore.Http.Internal
 
             if (callback != null)
             {
-                try
+                // Offload callbacks to avoid stack dives on sync completions.
+                var ignored = Task.Run(() =>
                 {
-                    callback(tcs.Task);
-                }
-                catch (Exception)
-                {
-                    // Suppress exceptions on background threads.
-                }
+                    try
+                    {
+                        callback(tcs.Task);
+                    }
+                    catch (Exception)
+                    {
+                        // Suppress exceptions on background threads.
+                    }
+                });
             }
         }
 
         public override int EndRead(IAsyncResult asyncResult)
         {
+            if (asyncResult == null)
+            {
+                throw new ArgumentNullException(nameof(asyncResult));
+            }
+
             var task = (Task<int>)asyncResult;
             return task.GetAwaiter().GetResult();
         }
diff --git a/src/Microsoft.AspNetCore.WebUtilities/BufferedReadStream.cs b/src/Microsoft.AspNetCore.WebUtilities/BufferedReadStream.cs
index f9ea281d05..6cf2fa7d11 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/BufferedReadStream.cs
+++ b/src/Microsoft.AspNetCore.WebUtilities/BufferedReadStream.cs
@@ -229,7 +229,18 @@ namespace Microsoft.AspNetCore.WebUtilities
                 tcs.TrySetResult(toCopy);
                 if (callback != null)
                 {
-                    callback(tcs.Task);
+                    // Offload callbacks to avoid stack dives on sync completions.
+                    var ignored = Task.Run(() =>
+                    {
+                        try
+                        {
+                            callback(tcs.Task);
+                        }
+                        catch (Exception)
+                        {
+                            // Suppress exceptions on background threads.
+                        }
+                    });
                 }
                 return tcs.Task;
             }
@@ -239,6 +250,11 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override int EndRead(IAsyncResult asyncResult)
         {
+            if (asyncResult == null)
+            {
+                throw new ArgumentNullException(nameof(asyncResult));
+            }
+
             Task<int> task = asyncResult as Task<int>;
             if (task != null)
             {
diff --git a/src/Microsoft.AspNetCore.WebUtilities/FileBufferingReadStream.cs b/src/Microsoft.AspNetCore.WebUtilities/FileBufferingReadStream.cs
index 06f9de2644..ada0c67bf4 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/FileBufferingReadStream.cs
+++ b/src/Microsoft.AspNetCore.WebUtilities/FileBufferingReadStream.cs
@@ -232,19 +232,28 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             if (callback != null)
             {
-                try
+                // Offload callbacks to avoid stack dives on sync completions.
+                var ignored = Task.Run(() =>
                 {
-                    callback(tcs.Task);
-                }
-                catch (Exception)
-                {
-                    // Suppress exceptions on background threads.
-                }
+                    try
+                    {
+                        callback(tcs.Task);
+                    }
+                    catch (Exception)
+                    {
+                        // Suppress exceptions on background threads.
+                    }
+                });
             }
         }
 
         public override int EndRead(IAsyncResult asyncResult)
         {
+            if (asyncResult == null)
+            {
+                throw new ArgumentNullException(nameof(asyncResult));
+            }
+
             var task = (Task<int>)asyncResult;
             return task.GetAwaiter().GetResult();
         }
diff --git a/src/Microsoft.AspNetCore.WebUtilities/MultipartReaderStream.cs b/src/Microsoft.AspNetCore.WebUtilities/MultipartReaderStream.cs
index c94b27b003..09f11959df 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/MultipartReaderStream.cs
+++ b/src/Microsoft.AspNetCore.WebUtilities/MultipartReaderStream.cs
@@ -184,19 +184,28 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             if (callback != null)
             {
-                try
+                // Offload callbacks to avoid stack dives on sync completions.
+                var ignored = Task.Run(() =>
                 {
-                    callback(tcs.Task);
-                }
-                catch (Exception)
-                {
-                    // Suppress exceptions on background threads.
-                }
+                    try
+                    {
+                        callback(tcs.Task);
+                    }
+                    catch (Exception)
+                    {
+                        // Suppress exceptions on background threads.
+                    }
+                });
             }
         }
 
         public override int EndRead(IAsyncResult asyncResult)
         {
+            if (asyncResult == null)
+            {
+                throw new ArgumentNullException(nameof(asyncResult));
+            }
+
             var task = (Task<int>)asyncResult;
             return task.GetAwaiter().GetResult();
         }