diff --git a/KashFlowApiClient/KashFlowApiClient.csproj b/KashFlowApiClient/KashFlowApiClient.csproj
index 587d901..9dd9411 100644
--- a/KashFlowApiClient/KashFlowApiClient.csproj
+++ b/KashFlowApiClient/KashFlowApiClient.csproj
@@ -60,7 +60,7 @@ v.1.0.0.0
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' ">
     <PackageReference Include="System.ComponentModel.Primitives" Version="4.3.0" />
     <PackageReference Include="System.Reflection.TypeExtensions" Version="4.4.0" />
-    <PackageReference Include="System.ServiceModel.Duplex" Version="4.0.1" />
+    <PackageReference Include="System.ServiceModel.Duplex" Version="4.0.4" />
     <PackageReference Include="System.ServiceModel.NetTcp" Version="4.1.0" />
     <PackageReference Include="System.ServiceModel.Security" Version="4.0.1" />
     <PackageReference Include="System.Xml.XmlSerializer" Version="4.0.11" />