--- sntp/tests/Makefile.in.orig	2015-10-27 12:47:07 UTC
+++ sntp/tests/Makefile.in
@@ -791,6 +791,7 @@ LDADD = \
 	$(base_LDADD)				\
 	$(top_builddir)/unity/libunity.a	\
 	$(LIBM)					\
+	$(PTHREAD_LIBS)				\
 	$(NULL)
 
 AM_CFLAGS = $(CFLAGS_NTP)