diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 1fa683c..a00532d 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -472,7 +472,7 @@
 	}
 	if (likely(sysctl_tcp_sack)) {
 		opts->options |= OPTION_SACK_ADVERTISE;
-		if (unlikely(!OPTION_TS & opts->options))
+		if (unlikely(!(OPTION_TS & opts->options)))
 			size += TCPOLEN_SACKPERM_ALIGNED;
 	}