diff --git a/lib/shared/ancestor-threads.js b/lib/shared/ancestor-threads.js
--- a/lib/shared/ancestor-threads.js
+++ b/lib/shared/ancestor-threads.js
@@ -14,7 +14,12 @@
 ): $ReadOnlyArray<ThreadInfo> {
   return useSelector(state => {
     if (!threadIsPending(threadInfo.id)) {
-      return ancestorThreadInfos(threadInfo.id)(state).slice(0, -1);
+      const ancestorThreads = ancestorThreadInfos(threadInfo.id)(state);
+      if (ancestorThreads.length > 1) {
+        return ancestorThreads.slice(0, -1);
+      }
+
+      return ancestorThreads;
     }
     const genesisThreadInfo = threadInfoSelector(state)[genesis.id];
     return genesisThreadInfo ? [genesisThreadInfo] : [];