2 files changed, 2 insertions, 2 deletions
diff --git a/src/mscorlib/shared/System/Threading/Tasks/TaskCanceledException.cs b/src/mscorlib/shared/System/Threading/Tasks/TaskCanceledException.cs
index d7690d4c7c..6657bcd36c 100644
--- a/src/mscorlib/shared/System/Threading/Tasks/TaskCanceledException.cs
+++ b/src/mscorlib/shared/System/Threading/Tasks/TaskCanceledException.cs
@@ -19,7 +19,6 @@ namespace System.Threading.Tasks
     /// <summary>
     /// Represents an exception used to communicate task cancellation.
     /// </summary>
-    [Serializable]
     public class TaskCanceledException : OperationCanceledException
     {
         [NonSerialized]
@@ -71,6 +70,7 @@ namespace System.Threading.Tasks
         /// <param name="context">The <see cref="T:System.Runtime.Serialization.StreamingContext"/> that contains contextual information about the source or destination. </param>
         protected TaskCanceledException(SerializationInfo info, StreamingContext context) : base(info, context)
         {
+            throw new PlatformNotSupportedException();
         }
 
         /// <summary>
diff --git a/src/mscorlib/shared/System/Threading/Tasks/TaskSchedulerException.cs b/src/mscorlib/shared/System/Threading/Tasks/TaskSchedulerException.cs
index 148b6300ef..2888415d0d 100644
--- a/src/mscorlib/shared/System/Threading/Tasks/TaskSchedulerException.cs
+++ b/src/mscorlib/shared/System/Threading/Tasks/TaskSchedulerException.cs
@@ -20,7 +20,6 @@ namespace System.Threading.Tasks
     /// Represents an exception used to communicate an invalid operation by a
     /// <see cref="T:System.Threading.Tasks.TaskScheduler"/>.
     /// </summary>
-    [Serializable]
     public class TaskSchedulerException : Exception
     {
         /// <summary>
@@ -72,6 +71,7 @@ namespace System.Threading.Tasks
         protected TaskSchedulerException(SerializationInfo info, StreamingContext context)
             : base(info, context)
         {
+            throw new PlatformNotSupportedException();
         }
     }
 }