diff --git a/UnitTests/UnitTests.csproj b/UnitTests/UnitTests.csproj
index e59718eece009ddafa4617b9a6cea55c4dda04b6..1853ebcc5302866acbec7c8f70309d563d2b5788 100644
--- a/UnitTests/UnitTests.csproj
+++ b/UnitTests/UnitTests.csproj
@@ -14,4 +14,7 @@
     <PackageReference Include="coverlet.collector" Version="3.1.0" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\Helios\Helios.csproj" />
+  </ItemGroup>
 </Project>