diff --git a/src/AsyncBridge/Properties/SpecificAssemblyInfo.cs b/src/AsyncBridge/Properties/SpecificAssemblyInfo.cs
new file mode 100644
index 0000000..fa00984
--- /dev/null
+++ b/src/AsyncBridge/Properties/SpecificAssemblyInfo.cs
@@ -0,0 +1,8 @@
+using System.Security;
+
+#if !NET35
+[assembly: AllowPartiallyTrustedCallers]
+#if !PORTABLE
+[assembly: SecurityRules(SecurityRuleSet.Level2)]
+#endif
+#endif
\ No newline at end of file
diff --git a/src/AsyncBridge/Runtime.CompilerServices/AsyncVoidMethodBuilder.cs b/src/AsyncBridge/Runtime.CompilerServices/AsyncVoidMethodBuilder.cs
index 9b7ddca..ffef163 100644
--- a/src/AsyncBridge/Runtime.CompilerServices/AsyncVoidMethodBuilder.cs
+++ b/src/AsyncBridge/Runtime.CompilerServices/AsyncVoidMethodBuilder.cs
@@ -79,6 +79,7 @@ private AsyncVoidMethodBuilder(SynchronizationContext synchronizationContext)
         /// <summary>
         /// Registers with UnobservedTaskException to suppress exception crashing.
         /// </summary>
+        [SecuritySafeCritical]
         internal static void PreventUnobservedTaskExceptions()
         {
             if (Interlocked.CompareExchange(ref s_preventUnobservedTaskExceptionsInvoked, 1, 0) != 0)
diff --git a/src/AsyncBridge/Runtime.CompilerServices/TaskAwaiter.cs b/src/AsyncBridge/Runtime.CompilerServices/TaskAwaiter.cs
index da73d85..46e3f3c 100644
--- a/src/AsyncBridge/Runtime.CompilerServices/TaskAwaiter.cs
+++ b/src/AsyncBridge/Runtime.CompilerServices/TaskAwaiter.cs
@@ -254,17 +254,27 @@ private static void RunNoException(Action continuation)
         ///   Copies the exception's stack trace so its stack trace isn't overwritten.
         /// </summary>
         /// <param name="exc"> The exception to prepare. </param>
+        [SecuritySafeCritical]
         internal static Exception PrepareExceptionForRethrow(Exception exc)
         {
             if (s_prepForRemoting != null)
             {
                 try
                 {
-                    s_prepForRemoting.Invoke(exc, s_emptyParams);
+#if !PORTABLE
+                    new PermissionSet(Security.Permissions.PermissionState.Unrestricted).Assert();
+#endif
+                    return (Exception)s_prepForRemoting.Invoke(exc, s_emptyParams);
                 }
                 catch
                 {
                 }
+#if !PORTABLE
+                finally
+                {
+                    CodeAccessPermission.RevertAssert();
+                }
+#endif
             }
             return exc;
         }
diff --git a/tests/AsyncBridge.Tests/PartialTrustTests.cs b/tests/AsyncBridge.Tests/PartialTrustTests.cs
new file mode 100644
index 0000000..3c31614
--- /dev/null
+++ b/tests/AsyncBridge.Tests/PartialTrustTests.cs
@@ -0,0 +1,273 @@
+using System;
+using System.Reflection;
+using System.Runtime.Serialization;
+using System.Security;
+using System.Security.Permissions;
+using System.Security.Policy;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+#if NET45
+using TaskEx = System.Threading.Tasks.Task;
+#endif
+
+#if NET45
+namespace ReferenceAsync.Tests
+#elif NET35
+namespace AsyncBridge.Net35.Tests
+#elif ATP
+namespace AsyncTargetingPack.Tests
+#else
+namespace AsyncBridge.Tests
+#endif
+{
+#if !ATP
+    public sealed class Sandbox : IDisposable
+    {
+        private readonly AppDomain _Sandbox;
+
+        public Sandbox()
+        {
+            var CurrentSetup = AppDomain.CurrentDomain.SetupInformation;
+            var MySetup = new AppDomainSetup()
+            {
+                ApplicationBase = CurrentSetup.ApplicationBase
+            };
+
+            var MyPermissions = new PermissionSet(PermissionState.None);
+            MyPermissions.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
+            // Ensure we can read our own assemblies and files
+            MyPermissions.AddPermission(new FileIOPermission(FileIOPermissionAccess.Read, CurrentSetup.ApplicationBase));
+
+            _Sandbox = AppDomain.CreateDomain(
+                "Partial Trust Tests",
+                AppDomain.CurrentDomain.Evidence,
+                MySetup,
+                MyPermissions,
+#if NET45
+                new StrongName[0]
+#else
+                // AsyncBridge and AsyncTargetingPack need full trust to work. The test classes remain untrusted
+                new StrongName[] { CreateStrongName(typeof(TaskEx).Assembly.GetName()) }
+#endif
+                );
+
+            _Sandbox.UnhandledException += OnUnhandledException;
+        }
+
+        public TRemote Create<TRemote>() where TRemote : MarshalByRefObject
+        {
+            // This does not demand ReflectionPermission, so we don't need to give the test assembly full trust
+            return (TRemote)Activator.CreateInstanceFrom(_Sandbox, typeof(TRemote).Assembly.ManifestModule.FullyQualifiedName, typeof(TRemote).FullName).Unwrap();
+        }
+
+        public void Dispose()
+        {
+            AppDomain.Unload(_Sandbox);
+        }
+
+        public static void OnUnhandledException(object sender, UnhandledExceptionEventArgs e)
+        {
+            Write.Line(string.Format("Unhandled Remote Exception {0}", e.ExceptionObject.ToString()));
+            throw new ApplicationException("Unhandled Remote Exception", (Exception)e.ExceptionObject);
+        }
+
+        private static StrongName CreateStrongName(AssemblyName assemblyName)
+        { //****************************************
+            var MyPublicKey = assemblyName.GetPublicKey();
+            //****************************************
+
+            if (MyPublicKey == null || MyPublicKey.Length == 0)
+                throw new InvalidOperationException(string.Format("Assembly Name for {0} must specify the full Public Key", assemblyName.Name));
+
+            return new StrongName(new StrongNamePublicKeyBlob(MyPublicKey), assemblyName.Name, assemblyName.Version);
+        }
+    }
+
+    [TestClass]
+    public class PartialTrustTests
+    {
+        public PartialTrustTests()
+        {
+            // Forces .Net to load the culture-specific assembly for exception messages BEFORE one gets raised from partial trust.
+            // If we don't do this, it will try to do so while in a partially trusted context,
+            // and get into an chain of failed AssemblyResolve calls, ending in a failed Assert for "mscorlib recursive resource lookup bug".
+            new ArgumentException();
+        }
+
+        [TestMethod]
+        public void CreateInSandbox()
+        {
+            using (var Sandbox = new Sandbox())
+            {
+                var RemoteObject = Sandbox.Create<CreateInSandboxClass>();
+                Assert.AreEqual("Hello", RemoteObject.SayHello());
+            }
+        }
+
+        public sealed class CreateInSandboxClass : MarshalByRefObject
+        {
+            public string SayHello()
+            {
+                return "Hello";
+            }
+        }
+
+        [TestMethod]
+        public void ExecuteTaskInSandbox()
+        {
+            using (var Sandbox = new Sandbox())
+            {
+                var RemoteObject = Sandbox.Create<ExecuteTaskInSandboxClass>();
+
+                RemoteObject.Execute();
+            }
+        }
+
+        public sealed class ExecuteTaskInSandboxClass : MarshalByRefObject
+        {
+            public void Execute()
+            {
+                TestUtils.RunAsync(async () =>
+                {
+                    await TaskEx.Yield();
+                });
+            }
+        }
+
+        [TestMethod]
+        public void ThrowTaskInSandbox()
+        {
+            using (var Sandbox = new Sandbox())
+            {
+                var RemoteObject = Sandbox.Create<ThrowTaskClass>();
+
+                try
+                {
+                    RemoteObject.Execute();
+
+                    Assert.Fail();
+                }
+                catch (InvalidOperationException e)
+                {
+                    Assert.AreEqual("Exception from Task", e.Message);
+                }
+            }
+        }
+
+        public sealed class ThrowTaskClass : MarshalByRefObject
+        {
+            public void Execute()
+            {
+                TestUtils.RunAsync(async () =>
+                {
+                    await TaskEx.Yield();
+
+                    throw new InvalidOperationException("Exception from Task");
+                });
+            }
+        }
+    
+        [TestMethod]
+        public void ThrowNestedTask()
+        {
+            var RemoteObject = new ThrowNestedTaskClass();
+
+            try
+            {
+                RemoteObject.Execute();
+
+                Assert.Fail();
+            }
+            catch (InvalidOperationException e)
+            {
+                Assert.AreEqual("Exception from Task", e.Message);
+            }
+        }
+
+        [TestMethod]
+        public void ThrowNestedTaskInSandbox()
+        {
+            using (var Sandbox = new Sandbox())
+            {
+                var RemoteObject = Sandbox.Create<ThrowNestedTaskClass>();
+
+                try
+                {
+                    RemoteObject.Execute();
+
+                    Assert.Fail();
+                }
+                catch (InvalidOperationException e)
+                {
+                    Assert.AreEqual("Exception from Task", e.Message);
+                }
+            }
+        }
+
+        public sealed class ThrowNestedTaskClass : MarshalByRefObject
+        {
+            public void Execute()
+            {
+                TestUtils.RunAsync(async () =>
+                {
+                    await TaskEx.Run(async () =>
+                    {
+                        await TaskEx.Yield();
+
+                        throw new InvalidOperationException("Exception from Task");
+                    });
+                });
+            }
+        }
+
+        [TestMethod]
+        public void ThrowCustomExceptionInSandbox()
+        {
+            using (var Sandbox = new Sandbox())
+            {
+                var RemoteObject = Sandbox.Create<ThrowCustomExceptionInSandboxClass>();
+
+                try
+                {
+                    RemoteObject.Execute();
+
+                    Assert.Fail();
+                }
+                catch (CustomException e)
+                {
+                    Assert.AreEqual("Exception from Task", e.Message);
+                }
+            }
+        }
+
+        public sealed class ThrowCustomExceptionInSandboxClass : MarshalByRefObject
+        {
+            public void Execute()
+            {
+                TestUtils.RunAsync(async () =>
+                {
+                    await TaskEx.Run(async () =>
+                    {
+                        await TaskEx.Yield();
+
+                        throw new CustomException("Exception from Task");
+                    });
+                });
+            }
+        }
+
+        [Serializable]
+        public sealed class CustomException : Exception
+        {
+            public CustomException(string message) : base(message)
+            {
+            }
+
+            public CustomException(SerializationInfo info, StreamingContext context) : base(info, context)
+            {
+            }
+        }
+    }
+#endif
+}