diff --git a/backend/ai-core/internal/background/thinker.go b/backend/ai-core/internal/background/thinker.go
index b0de429..755fd13 100644
--- a/backend/ai-core/internal/background/thinker.go
+++ b/backend/ai-core/internal/background/thinker.go
@@ -1096,7 +1096,6 @@ func (t *Thinker) performThink(triggerReason string) {
 	t.setLastThink(t.lastThinkTime)
 	t.incThinkCount()
 	currentCount := t.thinkCount()
-	t.muUnlock()
 
 	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
 	defer cancel()