diff --git a/WebJobs.Extensions.DurableTask.sln b/WebJobs.Extensions.DurableTask.sln
index 8efe24eee..353e83805 100644
--- a/WebJobs.Extensions.DurableTask.sln
+++ b/WebJobs.Extensions.DurableTask.sln
@@ -94,6 +94,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "PerfTests", "PerfTests", "{
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DFPerfScenariosV4", "test\DFPerfScenarios\DFPerfScenariosV4.csproj", "{FC8AD123-F949-4D21-B817-E5A4BBF7F69B}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Worker.Extensions.DurableTask.Tests", "test\Worker.Extensions.DurableTask.Tests\Worker.Extensions.DurableTask.Tests.csproj", "{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -178,6 +180,10 @@ Global
 		{FC8AD123-F949-4D21-B817-E5A4BBF7F69B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{FC8AD123-F949-4D21-B817-E5A4BBF7F69B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{FC8AD123-F949-4D21-B817-E5A4BBF7F69B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -211,6 +217,7 @@ Global
 		{65F904AA-0F6F-48CB-BE19-593B7D68152A} = {7387E723-E153-4B7A-B105-8C67BFBD48CF}
 		{7387E723-E153-4B7A-B105-8C67BFBD48CF} = {78BCF152-C22C-408F-9FB1-0F8C99B154B5}
 		{FC8AD123-F949-4D21-B817-E5A4BBF7F69B} = {7387E723-E153-4B7A-B105-8C67BFBD48CF}
+		{76DEC17C-BF6A-498A-8E8A-7D6CB2E03284} = {78BCF152-C22C-408F-9FB1-0F8C99B154B5}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {5E9AC327-DE18-41A5-A55D-E44CB4281943}
diff --git a/nuget.exe b/nuget.exe
new file mode 100644
index 000000000..d70c80b7f
Binary files /dev/null and b/nuget.exe differ
diff --git a/release_notes.md b/release_notes.md
index b5a489c99..9252a985d 100644
--- a/release_notes.md
+++ b/release_notes.md
@@ -1,11 +1,10 @@
 # Release Notes
 
-## Microsoft.Azure.Functions.Worker.Extensions.DurableTask 1.2.0
+## Microsoft.Azure.Functions.Worker.Extensions.DurableTask 1.2.1
 
 ### New Features
 
-- Add `suspendPostUri` and `resumePostUri` to the list of returned URIs in `CreateCheckStatusResponseAsync`. (https://github.com/Azure/azure-functions-durable-extension/pull/2785)
-- Fix `NotSupportedException` when calling `PurgeAllInstancesAsync` and `PurgeInstanceAsync`
+- Fix regression on `TerminateInstanceAsync` API causing invocations to fail with "unimplemented" exceptions (https://github.com/Azure/azure-functions-durable-extension/pull/2829).
 
 ### Bug Fixes
 
diff --git a/src/WebJobs.Extensions.DurableTask/WebJobs.Extensions.DurableTask.csproj b/src/WebJobs.Extensions.DurableTask/WebJobs.Extensions.DurableTask.csproj
index 44efb7506..d95a8bbb8 100644
--- a/src/WebJobs.Extensions.DurableTask/WebJobs.Extensions.DurableTask.csproj
+++ b/src/WebJobs.Extensions.DurableTask/WebJobs.Extensions.DurableTask.csproj
@@ -8,7 +8,7 @@
     <MinorVersion>0</MinorVersion>
     <PatchVersion>0</PatchVersion>
     <VersionPrefix>$(MajorVersion).$(MinorVersion).$(PatchVersion)</VersionPrefix>
-    <VersionSuffix>preview.3</VersionSuffix>
+    <VersionSuffix>preview.4</VersionSuffix>
     <FileVersion>$(MajorVersion).$(MinorVersion).$(PatchVersion)</FileVersion>
     <AssemblyVersion>$(MajorVersion).0.0.0</AssemblyVersion>
     <Company>Microsoft Corporation</Company>
@@ -124,7 +124,7 @@
 
   <!-- Common dependencies across all targets -->
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.DurableTask.Core" Version="2.17.0" />
+    <PackageReference Include="Microsoft.Azure.DurableTask.Core" Version="2.17.1" />
     <PackageReference Include="Microsoft.Azure.DurableTask.AzureStorage" Version="2.0.0-preview.6" />
     <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.DurableTask.Analyzers" Version="0.5.*" />
     <!-- Build-time dependencies -->
diff --git a/src/Worker.Extensions.DurableTask/AssemblyInfo.cs b/src/Worker.Extensions.DurableTask/AssemblyInfo.cs
index 32927df11..7f387ee55 100644
--- a/src/Worker.Extensions.DurableTask/AssemblyInfo.cs
+++ b/src/Worker.Extensions.DurableTask/AssemblyInfo.cs
@@ -1,7 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
+using System.Runtime.CompilerServices;
 using Microsoft.Azure.Functions.Worker.Extensions.Abstractions;
 
 // TODO: Find a way to generate this dynamically at build-time
-[assembly: ExtensionInformation("Microsoft.Azure.WebJobs.Extensions.DurableTask", "2.13.3")]
+[assembly: ExtensionInformation("Microsoft.Azure.WebJobs.Extensions.DurableTask", "2.13.4")]
+[assembly: InternalsVisibleTo("Worker.Extensions.DurableTask.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100cd1dabd5a893b40e75dc901fe7293db4a3caf9cd4d3e3ed6178d49cd476969abe74a9e0b7f4a0bb15edca48758155d35a4f05e6e852fff1b319d103b39ba04acbadd278c2753627c95e1f6f6582425374b92f51cca3deb0d2aab9de3ecda7753900a31f70a236f163006beefffe282888f85e3c76d1205ec7dfef7fa472a17b1")]
\ No newline at end of file
diff --git a/src/Worker.Extensions.DurableTask/FunctionsDurableTaskClient.cs b/src/Worker.Extensions.DurableTask/FunctionsDurableTaskClient.cs
index d47eef1f5..0f9231375 100644
--- a/src/Worker.Extensions.DurableTask/FunctionsDurableTaskClient.cs
+++ b/src/Worker.Extensions.DurableTask/FunctionsDurableTaskClient.cs
@@ -85,9 +85,9 @@ public override Task SuspendInstanceAsync(
     }
 
     public override Task TerminateInstanceAsync(
-        string instanceId, object? output = null, CancellationToken cancellation = default)
+        string instanceId, TerminateInstanceOptions? options = null, CancellationToken cancellation = default)
     {
-        return this.inner.TerminateInstanceAsync(instanceId, output, cancellation);
+        return this.inner.TerminateInstanceAsync(instanceId, options, cancellation);
     }
 
     public override Task<OrchestrationMetadata> WaitForInstanceCompletionAsync(
diff --git a/src/Worker.Extensions.DurableTask/HTTP/HttpMethodConverter.cs b/src/Worker.Extensions.DurableTask/HTTP/HttpMethodConverter.cs
index 540f1f981..933ec55d9 100644
--- a/src/Worker.Extensions.DurableTask/HTTP/HttpMethodConverter.cs
+++ b/src/Worker.Extensions.DurableTask/HTTP/HttpMethodConverter.cs
@@ -20,7 +20,8 @@ public override HttpMethod Read(
         Type objectType,
         JsonSerializerOptions options)
     {
-        return new HttpMethod(reader.GetString());
+        string readerString = reader.GetString() ?? string.Empty;
+        return new HttpMethod(readerString);
     }
 
     public override void Write(
diff --git a/src/Worker.Extensions.DurableTask/Worker.Extensions.DurableTask.csproj b/src/Worker.Extensions.DurableTask/Worker.Extensions.DurableTask.csproj
index 7a93ae655..b5c22a516 100644
--- a/src/Worker.Extensions.DurableTask/Worker.Extensions.DurableTask.csproj
+++ b/src/Worker.Extensions.DurableTask/Worker.Extensions.DurableTask.csproj
@@ -29,7 +29,7 @@
     <AssemblyOriginatorKeyFile>..\..\sign.snk</AssemblyOriginatorKeyFile>
 
     <!-- Version information -->
-    <VersionPrefix>1.1.3</VersionPrefix>
+    <VersionPrefix>1.1.4</VersionPrefix>
     <VersionSuffix></VersionSuffix>
     <AssemblyVersion>$(VersionPrefix).0</AssemblyVersion>
     <!-- FileVersionRevision is expected to be set by the CI.  -->
@@ -39,8 +39,8 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Azure.Functions.Worker.Core" Version="1.16.0" />
     <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Abstractions" Version="1.3.0" />
-    <PackageReference Include="Microsoft.DurableTask.Client.Grpc" Version="1.2.3" />
-    <PackageReference Include="Microsoft.DurableTask.Worker.Grpc" Version="1.2.3" />
+    <PackageReference Include="Microsoft.DurableTask.Client.Grpc" Version="1.2.4" />
+    <PackageReference Include="Microsoft.DurableTask.Worker.Grpc" Version="1.2.4" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/test/Worker.Extensions.DurableTask.Tests/FunctionsDurableTaskClientTests.cs b/test/Worker.Extensions.DurableTask.Tests/FunctionsDurableTaskClientTests.cs
new file mode 100644
index 000000000..5a335aefa
--- /dev/null
+++ b/test/Worker.Extensions.DurableTask.Tests/FunctionsDurableTaskClientTests.cs
@@ -0,0 +1,57 @@
+using Microsoft.DurableTask.Client;
+using Microsoft.DurableTask.Client.Grpc;
+using Moq;
+
+namespace Microsoft.Azure.Functions.Worker.Tests
+{
+    /// <summary>
+    /// Unit tests for <see cref="FunctionsDurableTaskClient />.
+    /// </summary>
+    public class FunctionsDurableTaskClientTests
+    {
+        private FunctionsDurableTaskClient GetTestFunctionsDurableTaskClient()
+        {
+            // construct mock client
+
+            // The DurableTaskClient demands a string parameter in it's constructor, so we pass it in
+            string clientName = string.Empty;
+            Mock<DurableTaskClient> durableClientMock = new(clientName);
+
+            Task completedTask = Task.CompletedTask;
+            durableClientMock.Setup(x => x.TerminateInstanceAsync(
+                It.IsAny<string>(), It.IsAny<TerminateInstanceOptions>(), It.IsAny<CancellationToken>())).Returns(completedTask);
+
+            DurableTaskClient durableClient = durableClientMock.Object;
+            FunctionsDurableTaskClient client = new FunctionsDurableTaskClient(durableClient, queryString: null);
+            return client;
+        }
+
+        /// <summary>
+        /// Test that the `TerminateInstnaceAsync` can be invoked without exceptions.
+        /// Exceptions are a risk since we inherit from an abstract class where default implementations are not provided.
+        /// </summary>
+        [Fact]
+        public async void TerminateDoesNotThrow()
+        {
+            FunctionsDurableTaskClient client = GetTestFunctionsDurableTaskClient();
+
+            string instanceId = string.Empty;
+            object output = string.Empty;
+            TerminateInstanceOptions options = new TerminateInstanceOptions();
+            CancellationToken token = CancellationToken.None;
+
+            // call terminate API with every possible parameter combination
+            // if we don't encounter any unimplemented exceptions from the abstract class,
+            // then the test passes
+
+            await client.TerminateInstanceAsync(instanceId, token);
+
+            await client.TerminateInstanceAsync(instanceId, output);
+            await client.TerminateInstanceAsync(instanceId, output, token);
+
+            await client.TerminateInstanceAsync(instanceId);
+            await client.TerminateInstanceAsync(instanceId, options);
+            await client.TerminateInstanceAsync(instanceId, options, token);
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/Worker.Extensions.DurableTask.Tests/Worker.Extensions.DurableTask.Tests.csproj b/test/Worker.Extensions.DurableTask.Tests/Worker.Extensions.DurableTask.Tests.csproj
new file mode 100644
index 000000000..e946c176c
--- /dev/null
+++ b/test/Worker.Extensions.DurableTask.Tests/Worker.Extensions.DurableTask.Tests.csproj
@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+
+    <!-- Sign assembly so it can reference internal components of the Worker Extension package -->
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>..\..\sign.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="xunit" Version="2.5.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
+    <PackageReference Include="Moq" Version="4.7.145" />
+    <ProjectReference Include="..\..\src\Worker.Extensions.DurableTask\Worker.Extensions.DurableTask.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+</Project>