diff --git a/Gwen/Gwen.csproj b/Gwen/Gwen.csproj
index 3120a5a..1cc12b8 100644
--- a/Gwen/Gwen.csproj
+++ b/Gwen/Gwen.csproj
@@ -32,6 +32,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
+    <Reference Include="System.Core" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>