diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -902,10 +902,10 @@
  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
  * binary point, and is smoothed with an ALPHA of 0.75.
  */
-#define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
-#define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
-#define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
-#define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
+#define	TCP_RTT_SCALE		32	/* multiplier for srtt; 5 bits frac. */
+#define	TCP_RTT_SHIFT		5	/* shift for srtt; 5 bits frac. */
+#define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 4 bits */
+#define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 4 bits */
 #define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
 
 /*