diff --git a/lib/libsm/Makefile b/lib/libsm/Makefile
index ae76e91ccd1c..ce590d71f058 100644
--- a/lib/libsm/Makefile
+++ b/lib/libsm/Makefile
@@ -7,6 +7,7 @@ SENDMAIL_DIR=${.CURDIR}/../../contrib/sendmail
 
 CFLAGS+=-I${SENDMAIL_DIR}/src -I${SENDMAIL_DIR}/include -I.
 CFLAGS+=-DNEWDB -DNIS -DMAP_REGEX -DNOT_SENDMAIL
+CFLAGS+=-DHAVE_NANOSLEEP
 
 .if ${MK_INET6_SUPPORT} != "no"
 CFLAGS+=-DNETINET6