diff --git a/sys/dev/etherswitch/arswitch/arswitch_reg.c b/sys/dev/etherswitch/arswitch/arswitch_reg.c
index 0c0e9153b2e..4a2fa6a977a 100644
--- a/sys/dev/etherswitch/arswitch/arswitch_reg.c
+++ b/sys/dev/etherswitch/arswitch/arswitch_reg.c
@@ -148,7 +148,7 @@ int
 arswitch_writereg_msb(device_t dev, int addr, int data)
 {
 
-	return (arswitch_writereg16(dev, addr + 2, data >> 16));
+	return (arswitch_writereg16(dev, addr + 2, (data >> 16) & 0xffff));
 }
 
 int