diff --git a/include/st30_api.h b/include/st30_api.h
index ffb596b0e..98f73fd13 100644
--- a/include/st30_api.h
+++ b/include/st30_api.h
@@ -349,7 +349,7 @@ struct st30_tx_ops {
  * Include the PCIE port and other required info
  */
 struct st30_rx_ops {
-  /** Mandatory. source IP address of sender */
+  /** Mandatory. source IP address of sender or multicast IP address */
   uint8_t sip_addr[MTL_SESSION_PORT_MAX][MTL_IP_ADDR_LEN];
   /** Mandatory. 1 or 2, num of ports this session attached to */
   uint8_t num_port;
@@ -371,6 +371,8 @@ struct st30_rx_ops {
   /** Mandatory. 7 bits payload type define in RFC3550 */
   uint8_t payload_type;
 
+  /** Optional. source filter IP address of multicast */
+  uint8_t mcast_sip_addr[MTL_SESSION_PORT_MAX][MTL_IP_ADDR_LEN];
   /** Optional. Synchronization source defined in RFC3550, RX session will check the
    * incoming RTP packets match the ssrc. Leave to zero to disable the ssrc check */
   uint32_t ssrc;
diff --git a/include/st40_api.h b/include/st40_api.h
index dd715e0a4..eb92fc660 100644
--- a/include/st40_api.h
+++ b/include/st40_api.h
@@ -298,7 +298,7 @@ struct st40_tx_ops {
  * Include the PCIE port and other required info
  */
 struct st40_rx_ops {
-  /** Mandatory. source IP address of sender */
+  /** Mandatory. source IP address of sender or multicast IP address */
   uint8_t sip_addr[MTL_SESSION_PORT_MAX][MTL_IP_ADDR_LEN];
   /** Mandatory. 1 or 2, num of ports this session attached to */
   uint8_t num_port;
@@ -310,6 +310,8 @@ struct st40_rx_ops {
   /** Mandatory. 7 bits payload type define in RFC3550 */
   uint8_t payload_type;
 
+  /** Optional. source filter IP address of multicast */
+  uint8_t mcast_sip_addr[MTL_SESSION_PORT_MAX][MTL_IP_ADDR_LEN];
   /** Optional. Synchronization source defined in RFC3550, RX session will check the
    * incoming RTP packets match the ssrc. Leave to zero to disable the ssrc check */
   uint32_t ssrc;