diff --git a/rate/rate_test.go b/rate/rate_test.go
index c91fc8f..c9bc239 100644
--- a/rate/rate_test.go
+++ b/rate/rate_test.go
@@ -192,7 +192,7 @@
 	tt.advanceUnlocked(dur)
 }
 
-// advanceUnlock advances the fake time, assuming it is already locked.
+// advanceUnlocked advances the fake time, assuming it is already locked.
 func (tt *testTime) advanceUnlocked(dur time.Duration) {
 	tt.cur = tt.cur.Add(dur)
 	i := 0