diff --git a/libraries/liblber/lber-int.h b/libraries/liblber/lber-int.h
index aeab66b2ba..719f329da4 100644
--- a/libraries/liblber/lber-int.h
+++ b/libraries/liblber/lber-int.h
@@ -166,6 +166,14 @@ LDAP_F int lber_log_sos_dump LDAP_P((
 	int loglvl,
 	Seqorset *sos ));
 
+/* io.c */
+LDAP_F	Sockbuf *lber_pvt_sb_alloc	LDAP_P(( void ));
+LDAP_F	Sockbuf *lber_pvt_sb_alloc_fd	LDAP_P(( int ));
+LDAP_F	Sockbuf *lber_pvt_sb_alloc_fd	LDAP_P(( int ));
+LDAP_F	void	lber_pvt_sb_free	LDAP_P(( Sockbuf * ));
+LDAP_F	int	lber_pvt_sb_get_option	LDAP_P(( Sockbuf *, int, void * ));
+LDAP_F	int	lber_pvt_sb_set_option	LDAP_P(( Sockbuf *, int, void * ));
+
 /* sockbuf.c */
 
 LDAP_F	int lber_pvt_sb_init LDAP_P(( Sockbuf *sb ));