diff --git a/src/pkg/time/sleep.go b/src/pkg/time/sleep.go
index 79ca3b6ca3d..fe0ddce4a9b 100644
--- a/src/pkg/time/sleep.go
+++ b/src/pkg/time/sleep.go
@@ -9,6 +9,7 @@ import (
 	"syscall"
 )
 
-// Sleep pauses the current goroutine for ns nanoseconds.
-// It returns os.EINTR if interrupted.
+// Sleep pauses the current goroutine for at least ns nanoseconds. Higher resolution
+// sleeping may be provided by syscall.Nanosleep on some operating systems.
+// Sleep returns os.EINTR if interrupted.
 func Sleep(ns int64) os.Error { return os.NewSyscallError("sleep", syscall.Sleep(ns)) }