diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c
index d82a962c6c1..6554399e06e 100644
--- a/sys/netinet/sctp_input.c
+++ b/sys/netinet/sctp_input.c
@@ -2616,7 +2616,7 @@ sctp_handle_cookie_echo(struct mbuf *m, int iphlen, int offset,
 		    (sizeof(uint32_t))));
 		diff = now;
 		timevalsub(&diff, &time_expires);
-		if (diff.tv_sec > UINT32_MAX / 1000000) {
+		if ((uint32_t)diff.tv_sec > UINT32_MAX / 1000000) {
 			staleness = UINT32_MAX;
 		} else {
 			staleness = diff.tv_sec * 1000000;