diff --git a/lib/libunbound/Makefile b/lib/libunbound/Makefile
index 5cafca793c72..4cbd5cdbb6e9 100644
--- a/lib/libunbound/Makefile
+++ b/lib/libunbound/Makefile
@@ -29,6 +29,7 @@ SRCS=	alloc.c as112.c autotrust.c cachedb.c config_file.c configlexer.l \
 	val_utils.c validator.c view.c winsock_event.c wire2str.c
 
 WARNS?=	3
+NO_WTHREAD_SAFETY= true
 
 LIBADD=	ssl crypto pthread
 
diff --git a/usr.sbin/unbound/Makefile.inc b/usr.sbin/unbound/Makefile.inc
index 20cac57b1b79..906b392dc8b1 100644
--- a/usr.sbin/unbound/Makefile.inc
+++ b/usr.sbin/unbound/Makefile.inc
@@ -1,6 +1,7 @@
 # $FreeBSD$
 
-NO_WERROR= true
+NO_WERROR=	true
+NO_WTHREAD_SAFETY= true
 PACKAGE=	unbound
 
 .include "../Makefile.inc"