diff --git a/math/ipopt/Makefile b/math/ipopt/Makefile
index 7c2dcef562a6..e0795acfacf7 100644
--- a/math/ipopt/Makefile
+++ b/math/ipopt/Makefile
@@ -4,7 +4,7 @@
 PORTNAME=	Ipopt
 DISTVERSION=	3.12.13
 CATEGORIES=	math
-MASTER_SITES=	http://www.coin-or.org/download/source/Ipopt/ \
+MASTER_SITES=	https://www.coin-or.org/download/source/Ipopt/ \
 		http://glaros.dtc.umn.edu/gkhome/fetch/sw/metis/OLD/:metis \
 		http://mumps.enseeiht.fr/:mumps
 DISTFILES=	${DISTNAME}${EXTRACT_SUFX} \