diff --git a/rate/rate.go b/rate/rate.go
index f0e0cf3..8f6c7f4 100644
--- a/rate/rate.go
+++ b/rate/rate.go
@@ -52,6 +52,8 @@
 // or its associated context.Context is canceled.
 //
 // The methods AllowN, ReserveN, and WaitN consume n tokens.
+//
+// Limiter is safe for simultaneous use by multiple goroutines.
 type Limiter struct {
 	mu     sync.Mutex
 	limit  Limit