diff --git a/app/invite/[code]/actions.ts b/app/invite/[code]/actions.ts
index 06e0c77..5967b96 100644
--- a/app/invite/[code]/actions.ts
+++ b/app/invite/[code]/actions.ts
@@ -58,6 +58,11 @@ export async function acceptInvite(
       userId,
       collectionId: invite.collectionId,
       accessLevel: invite.accessLevel,
+      // TODO: find a better way to enforce a specific testsolver type
+      ...(invite.collection.cid === "topsoj" && {
+        testsolverType: "Serious",
+        seriousTestsolverStartedAt: invite.collection.createdAt,
+      }),
     },
   });
 
diff --git a/components/sidebar.tsx b/components/sidebar.tsx
index 284b899..8196a87 100644
--- a/components/sidebar.tsx
+++ b/components/sidebar.tsx
@@ -25,6 +25,11 @@ export default function Sidebar({ children }: { children: React.ReactNode }) {
       label: "OTIS Mock AIME",
       active: pathname !== null && pathname.startsWith("/c/otis-mock-aime"),
     },
+    {
+      href: "/c/topsoj",
+      label: "TopsOJ",
+      active: pathname !== null && pathname.startsWith("/c/topsoj"),
+    },
   ];
 
   return (