diff --git a/pimd/pim_msdp.c b/pimd/pim_msdp.c
index bea74ff7d4..0c87b3f485 100644
--- a/pimd/pim_msdp.c
+++ b/pimd/pim_msdp.c
@@ -1066,8 +1066,7 @@ struct pim_msdp_peer *pim_msdp_peer_add(struct pim_instance *pim,
 	return mp;
 }
 
-struct pim_msdp_peer *pim_msdp_peer_find(struct pim_instance *pim,
-					 struct in_addr peer_addr)
+struct pim_msdp_peer *pim_msdp_peer_find(const struct pim_instance *pim, struct in_addr peer_addr)
 {
 	struct pim_msdp_peer lookup;
 
diff --git a/pimd/pim_msdp.h b/pimd/pim_msdp.h
index f01f575e07..cd1f6647f6 100644
--- a/pimd/pim_msdp.h
+++ b/pimd/pim_msdp.h
@@ -235,8 +235,7 @@ void pim_msdp_init(struct pim_instance *pim, struct event_loop *master);
 void pim_msdp_exit(struct pim_instance *pim);
 char *pim_msdp_state_dump(enum pim_msdp_peer_state state, char *buf,
 			  int buf_size);
-struct pim_msdp_peer *pim_msdp_peer_find(struct pim_instance *pim,
-					 struct in_addr peer_addr);
+struct pim_msdp_peer *pim_msdp_peer_find(const struct pim_instance *pim, struct in_addr peer_addr);
 void pim_msdp_peer_established(struct pim_msdp_peer *mp);
 void pim_msdp_peer_pkt_rxed(struct pim_msdp_peer *mp);
 void pim_msdp_peer_stop_tcp_conn(struct pim_msdp_peer *mp, bool chg_state);