diff --git a/lib/mux/queue.go b/lib/mux/queue.go
index 212563cf..6f14faaf 100644
--- a/lib/mux/queue.go
+++ b/lib/mux/queue.go
@@ -209,10 +209,15 @@ func NewListElement(buf []byte, l uint16, part bool) (element *common.ListElemen
 }
 
 type ReceiveWindowQueue struct {
-	lengthWait uint64
 	chain      *bufChain
 	stopOp     chan struct{}
 	readOp     chan struct{}
+	lengthWait uint64 // really strange ???? need put here
+	// https://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	// On non-Linux ARM, the 64-bit functions use instructions unavailable before the ARMv6k core.
+	// On ARM, x86-32, and 32-bit MIPS, it is the caller's responsibility
+	// to arrange for 64-bit alignment of 64-bit words accessed atomically.
+	// The first word in a variable or in an allocated struct, array, or slice can be relied upon to be 64-bit aligned.
 	timeout    time.Time
 }