diff --git a/lib/libsm/Makefile b/lib/libsm/Makefile
index 7a26a520b5b7..12a73d7e6d42 100644
--- a/lib/libsm/Makefile
+++ b/lib/libsm/Makefile
@@ -25,7 +25,7 @@ SRCS+=	assert.c debug.c errstring.c exc.c heap.c match.c rpool.c \
 	vasprintf.c vfprintf.c vfscanf.c vprintf.c vsnprintf.c \
 	wbuf.c wsetup.c string.c stringf.c \
 	xtrap.c strto.c test.c path.c strcasecmp.c strrevcmp.c \
-	signal.c clock.c config.c shm.c mbdb.c strexit.c cf.c ldap.c \
+	signal.c clock.c config.c sem.c shm.c mbdb.c strexit.c cf.c ldap.c \
 	niprop.c mpeix.c
 CLEANFILES+=sm_os.h