diff --git a/SVSim.BattleNode/SVSim.BattleNode.csproj b/SVSim.BattleNode/SVSim.BattleNode.csproj
index cff6997..032734e 100644
--- a/SVSim.BattleNode/SVSim.BattleNode.csproj
+++ b/SVSim.BattleNode/SVSim.BattleNode.csproj
@@ -8,7 +8,14 @@
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="MessagePack" Version="2.5.172" />
   </ItemGroup>
+  <ItemGroup>
+    <!-- Aliased: the copied decompiled engine puts a huge type surface in the GLOBAL namespace
+         (BattlePlayer, MessagePackSerializer, ...) which would otherwise leak into and collide
+         with every node file. The extern alias confines it; only Sessions/Engine/* opts in. -->
+    <ProjectReference Include="..\SVSim.BattleEngine\SVSim.BattleEngine.csproj" Aliases="engine" />
+  </ItemGroup>
   <ItemGroup>
     <InternalsVisibleTo Include="SVSim.UnitTests" />
+    <InternalsVisibleTo Include="SVSim.BattleEngine.Tests" />
   </ItemGroup>
 </Project>