diff --git a/src/libosmo-mgcp/mgcp_osmux.c b/src/libosmo-mgcp/mgcp_osmux.c
index 5d168260d..f8422321b 100644
--- a/src/libosmo-mgcp/mgcp_osmux.c
+++ b/src/libosmo-mgcp/mgcp_osmux.c
@@ -515,12 +515,12 @@ int osmux_enable_conn(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn,
 	 *  used to reconstruct the RTP flow from osmux. The RTP SSRC is
 	 *  allocated based on the circuit ID (conn_net->osmux.cid), which is unique
 	 *  in the local scope to the BSC/BSC-NAT. We use it to divide the RTP
-	 *  SSRC space (2^32) by the 256 possible circuit IDs, then randomly
+	 *  SSRC space (2^32) by the OSMUX_CID_MAX + 1 possible circuit IDs, then randomly
 	 *  select one value from that window. Thus, we have no chance to have
 	 *  overlapping RTP SSRC traveling to the BTSes behind the BSC,
 	 *  similarly, for flows traveling to the MSC.
 	 */
-	static const uint32_t rtp_ssrc_winlen = UINT32_MAX / 256;
+	static const uint32_t rtp_ssrc_winlen = UINT32_MAX / (OSMUX_CID_MAX + 1);
 	uint16_t osmux_dummy = endp->cfg->osmux_dummy;
 
 	/* Check if osmux is enabled for the specified connection */