diff --git a/plugins/linkedin-thought-leadership/hooks/scripts/session-start.mjs b/plugins/linkedin-thought-leadership/hooks/scripts/session-start.mjs
index 9ee2816..ea09793 100644
--- a/plugins/linkedin-thought-leadership/hooks/scripts/session-start.mjs
+++ b/plugins/linkedin-thought-leadership/hooks/scripts/session-start.mjs
@@ -149,6 +149,19 @@ if (existsSync(STATE_FILE)) {
     weekResetNote = `Warning: Week rollover failed (${err.message}). Manual reset may be needed.`;
   }
 
+  // Auto-prune Recent Posts entries older than 90 days
+  try {
+    const currentState = readFileSync(STATE_FILE, 'utf-8');
+    const { pruneContentHistory } = await import('./state-updater.mjs');
+    const pruneResult = pruneContentHistory(currentState, 90);
+    if (pruneResult && pruneResult.pruned > 0) {
+      writeFileSync(STATE_FILE, pruneResult.content, 'utf-8');
+      weekResetNote += (weekResetNote ? ' ' : '') + `Auto-pruned ${pruneResult.pruned} posts older than 90 days from Recent Posts.`;
+    }
+  } catch {
+    // Non-critical: don't block session start on pruning failure
+  }
+
   // Build status line
   let statusLine = `LinkedIn: ${postsThisWeek}/${weeklyGoal} posts this week | Streak: ${currentStreak} days`;
   if (lastPostDate && lastPostDate !== 'null') {