diff --git a/AwsEncryptionSDK/runtimes/net/CHANGELOG.md b/AwsEncryptionSDK/runtimes/net/CHANGELOG.md
index 3a51ab1a7..f4751fab1 100644
--- a/AwsEncryptionSDK/runtimes/net/CHANGELOG.md
+++ b/AwsEncryptionSDK/runtimes/net/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 4.1.1
+
+### Notes
+
+Update .csproj files to prevent use of AWS-SDK-NET V4
+
 ## 4.1.0
 
 ### Notes
diff --git a/AwsEncryptionSDK/runtimes/net/ESDK.csproj b/AwsEncryptionSDK/runtimes/net/ESDK.csproj
index 0429623a6..c16f78f88 100644
--- a/AwsEncryptionSDK/runtimes/net/ESDK.csproj
+++ b/AwsEncryptionSDK/runtimes/net/ESDK.csproj
@@ -8,7 +8,7 @@
       <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
       <IsPackable>true</IsPackable>
       
-      <Version>4.1.0</Version>
+      <Version>4.1.1</Version>
 
       <AssemblyName>AWS.Cryptography.EncryptionSDK</AssemblyName>
       <PackageId>AWS.Cryptography.EncryptionSDK</PackageId>
@@ -30,10 +30,8 @@
 
   <ItemGroup>
       <!-- TODO: manually upgraded to match the latest from MPL, is that reasonable? -->
-      <PackageReference Include="AWSSDK.Core" Version="3.7.*" />
       <PackageReference Include="DafnyRuntime" Version="4.9.0" />
-      <PackageReference Include="BouncyCastle.Cryptography" Version="2.3.1" />
-      <ProjectReference Include="../../../mpl/AwsCryptographicMaterialProviders/runtimes/net/MPL.csproj" />
+      <PackageReference Include="AWS.Cryptography.MaterialProviders" Version="[1.7.6]" />
       <!--
         System.Collections.Immutable can be removed once dafny.msbuild is updated with
         https://github.com/dafny-lang/dafny.msbuild/pull/10 and versioned
diff --git a/mpl b/mpl
index ec013f6ba..df37a708c 160000
--- a/mpl
+++ b/mpl
@@ -1 +1 @@
-Subproject commit ec013f6ba85d62ab41db48fec92baca85625e4b9
+Subproject commit df37a708cae023ae88a7d0dd0f3ecb59753be5f5