diff --git a/nimble/host/mesh/src/crypto.h b/nimble/host/mesh/src/crypto.h
index 637d13e72..dbdedf1fd 100644
--- a/nimble/host/mesh/src/crypto.h
+++ b/nimble/host/mesh/src/crypto.h
@@ -70,7 +70,7 @@ static inline int bt_mesh_beacon_key(const uint8_t net_key[16],
 }
 
 int bt_mesh_beacon_auth(const uint8_t beacon_key[16], uint8_t flags,
-			const uint8_t net_id[16], uint32_t iv_index,
+			const uint8_t net_id[8], uint32_t iv_index,
 			uint8_t auth[8]);
 
 static inline int bt_mesh_app_id(const uint8_t app_key[16], uint8_t app_id[1])