diff --git a/sbin/dumpon/Makefile b/sbin/dumpon/Makefile
index d0700ab16a89..71afa396ce5c 100644
--- a/sbin/dumpon/Makefile
+++ b/sbin/dumpon/Makefile
@@ -8,6 +8,7 @@ PROG=	dumpon
 .if ${MK_OPENSSL} != "no"
 LIBADD=	crypto
 CFLAGS+=-DHAVE_CRYPTO
+CFLAGS+=-DOPENSSL_API_COMPAT=0x10100000L
 .endif
 
 MAN=	dumpon.8