diff --git a/TODO-RELEASE b/TODO-RELEASE
index e44305bad..8c7cd96a8 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -25,3 +25,4 @@
 #
 #library		what		description / commit summary line
 osmo-mgw        update osmo-gsm-manuals dependency to > 0.3.0 for vty_cpu_sched.adoc include
+libosmo-mgcp-client     mgcp_response, mgcp_conn_peer   struct size change, breaks ABI
diff --git a/include/osmocom/mgcp_client/mgcp_client.h b/include/osmocom/mgcp_client/mgcp_client.h
index d4dd2d973..8914cc220 100644
--- a/include/osmocom/mgcp_client/mgcp_client.h
+++ b/include/osmocom/mgcp_client/mgcp_client.h
@@ -75,7 +75,7 @@ struct mgcp_response {
 	char *body;
 	struct mgcp_response_head head;
 	uint16_t audio_port;
-	char audio_ip[INET_ADDRSTRLEN];
+	char audio_ip[INET6_ADDRSTRLEN];
 	unsigned int ptime;
 	enum mgcp_codecs codecs[MGCP_MAX_CODECS];
 	unsigned int codecs_len;
diff --git a/include/osmocom/mgcp_client/mgcp_client_fsm.h b/include/osmocom/mgcp_client/mgcp_client_fsm.h
index a1ebbb69f..e31575317 100644
--- a/include/osmocom/mgcp_client/mgcp_client_fsm.h
+++ b/include/osmocom/mgcp_client/mgcp_client_fsm.h
@@ -15,7 +15,7 @@
  *  sure it is correct. */
 struct mgcp_conn_peer {
 	/*! RTP connection IP-Address (optional, string e.g. "127.0.0.1") */
-	char addr[INET_ADDRSTRLEN];
+	char addr[INET6_ADDRSTRLEN];
 
 	/*! RTP connection IP-Port (optional)  */
 	uint16_t port;
diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index b1909f0bd..146a59d59 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -1121,7 +1121,7 @@ static int add_sdp(struct msgb *msg, struct mgcp_msg *mgcp_msg, struct mgcp_clie
 {
 	unsigned int i;
 	int rc = 0;
-	char local_ip[INET_ADDRSTRLEN];
+	char local_ip[INET6_ADDRSTRLEN];
 	const char *codec;
 	unsigned int pt;