diff --git a/src/PepperDash.Essentials.Core/PepperDash.Essentials.Core.csproj b/src/PepperDash.Essentials.Core/PepperDash.Essentials.Core.csproj
index b1406d69..5c7c496d 100644
--- a/src/PepperDash.Essentials.Core/PepperDash.Essentials.Core.csproj
+++ b/src/PepperDash.Essentials.Core/PepperDash.Essentials.Core.csproj
@@ -25,6 +25,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Crestron.SimplSharp.SDK.ProgramLibrary" Version="2.21.90" />
+    <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />
   </ItemGroup>
   <ItemGroup>
     <None Include="Crestron\CrestronGenericBaseDevice.cs.orig" />