Index: head/sys/netinet/sctp_usrreq.c
===================================================================
--- head/sys/netinet/sctp_usrreq.c
+++ head/sys/netinet/sctp_usrreq.c
@@ -143,7 +143,10 @@
 					    chk->rec.data.tsn);
 				}
 				/* Clear any time so NO RTT is being done */
-				chk->do_rtt = 0;
+				if (chk->do_rtt == 1) {
+					chk->do_rtt = 0;
+					chk->whoTo->rto_needed = 1;
+				}
 			}
 		}
 	}