diff --git a/internal/state/state.go b/internal/state/state.go
index fca7276..dd4561d 100644
--- a/internal/state/state.go
+++ b/internal/state/state.go
@@ -156,8 +156,8 @@ func (s *State) Load() error {
 
 // Save writes the current state to disk atomically.
 func (s *State) Save() error {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
+	s.mu.Lock()
+	defer s.mu.Unlock()
 
 	s.snapshot.LastUpdated = time.Now().UTC()