diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bc8e2f45..263ced29 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -36,6 +36,24 @@ jobs:
           ref: fire-egg-dev
           path: test-server/cpp-v2-transition-server/aws-sdk-cpp/
 
+      - name: Checkout .NET V2 code
+        uses: actions/checkout@v5
+        with:
+          token: ${{ secrets.PAT_FOR_DOTNET }}
+          repository: aws/private-amazon-s3-encryption-client-dotnet-staging
+          # This is the branch for S3EC .NET V2
+          ref: v3sdk-development 
+          path: test-server/net-v2-v3-server/s3ec-net-v2/
+
+      - name: Checkout .NET V3 code
+        uses: actions/checkout@v5
+        with:
+          token: ${{ secrets.PAT_FOR_DOTNET }}
+          repository: aws/private-amazon-s3-encryption-client-dotnet-staging
+          # This is the branch for S3EC .NET V3
+          ref: s3ec-v3
+          path: test-server/net-v2-v3-server/s3ec-net-v3
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
diff --git a/.gitmodules b/.gitmodules
index 659db28b..0bf186eb 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -31,3 +31,11 @@
 	path = test-server/php-v2-transition-server/local-php-sdk
 	url = git@github.com:aws/private-aws-sdk-php-staging.git
 	branch = s3ec/transitional
+[submodule "test-server/net-v2-v3-server/s3ec-net-v2"]
+	path = test-server/net-v2-v3-server/s3ec-net-v2
+	url = https://github.com/aws/private-amazon-s3-encryption-client-dotnet-staging.git
+	branch = v3sdk-development
+[submodule "test-server/net-v2-v3-server/s3ec-net-v3"]
+	path = test-server/net-v2-v3-server/s3ec-net-v3
+	url = https://github.com/aws/private-amazon-s3-encryption-client-dotnet-staging.git
+	branch = s3ec-v3
diff --git a/test-server/net-v2-v3-server/NetV2V3Server.csproj b/test-server/net-v2-v3-server/NetV2V3Server.csproj
index a803a838..8d664eff 100644
--- a/test-server/net-v2-v3-server/NetV2V3Server.csproj
+++ b/test-server/net-v2-v3-server/NetV2V3Server.csproj
@@ -4,6 +4,7 @@
         <TargetFramework>net8.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
+        <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
     </PropertyGroup>
 
     <PropertyGroup>
@@ -19,11 +20,15 @@
     </PropertyGroup>
 
     <ItemGroup Condition="'$(S3EncryptionVersion)' == 'v2'">
-        <PackageReference Include="Amazon.Extensions.S3.Encryption" Version="2.2.1"/>
+        <ProjectReference Include="s3ec-net-v2/src/Amazon.Extensions.S3.Encryption.csproj"/>
     </ItemGroup>
 
     <ItemGroup Condition="'$(S3EncryptionVersion)' == 'v3'">
-        <PackageReference Include="Amazon.Extensions.S3.Encryption" Version="3.0.0"/>
+        <ProjectReference Include="s3ec-net-v3/src/Amazon.Extensions.S3.Encryption.csproj"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <Compile Include="**/*.cs" Exclude="s3ec-net-*/**/*.cs" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/test-server/net-v2-v3-server/s3ec-net-v2 b/test-server/net-v2-v3-server/s3ec-net-v2
new file mode 160000
index 00000000..ba85c07e
--- /dev/null
+++ b/test-server/net-v2-v3-server/s3ec-net-v2
@@ -0,0 +1 @@
+Subproject commit ba85c07e0706bae8df242fb7bbfa7e53a264bafa
diff --git a/test-server/net-v2-v3-server/s3ec-net-v3 b/test-server/net-v2-v3-server/s3ec-net-v3
new file mode 160000
index 00000000..cc942cb5
--- /dev/null
+++ b/test-server/net-v2-v3-server/s3ec-net-v3
@@ -0,0 +1 @@
+Subproject commit cc942cb541a733a4340f46bd3e4a1d29a9cbb9a3