diff --git a/Mono.Addins.CecilReflector/Mono.Addins.CecilReflector.csproj b/Mono.Addins.CecilReflector/Mono.Addins.CecilReflector.csproj
index 0630601..c66fbc3 100644
--- a/Mono.Addins.CecilReflector/Mono.Addins.CecilReflector.csproj
+++ b/Mono.Addins.CecilReflector/Mono.Addins.CecilReflector.csproj
@@ -40,6 +40,7 @@
     <PackOnBuild>True</PackOnBuild>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="System" />
     <Reference Include="System.Core" />
     <PackageReference Include="Mono.Cecil" Version="0.10.0-beta6" />
     <PackageReference Include="NuGet.Build.Packaging" Version="0.2.0" />