diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 9fb5d300a..74b1491bb 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -1024,11 +1024,19 @@ static int client_node_port_buffers(void *data,
 			return -EINVAL;
 
 		for (j = 0; j < newbuf->n_datas; j++) {
-			oldbuf->datas[j] = newbuf->datas[j];
+			struct spa_chunk *oldchunk = oldbuf->datas[j].chunk;
 
-			spa_log_debug(this->log, " data %d type:%d fd:%d", j,
+			/* overwrite everything except the chunk */
+			oldbuf->datas[j] = newbuf->datas[j];
+			oldbuf->datas[j].chunk = oldchunk;
+
+			spa_log_debug(this->log, " data %d type:%d fl:%08x fd:%d, offs:%d max:%d",
+					j,
 					newbuf->datas[j].type,
-					(int) newbuf->datas[j].fd);
+					newbuf->datas[j].flags,
+					(int) newbuf->datas[j].fd,
+					newbuf->datas[j].mapoffset,
+					newbuf->datas[j].maxsize);
 		}
 	}
 	mix->n_buffers = n_buffers;
diff --git a/src/modules/module-client-node/protocol-native.c b/src/modules/module-client-node/protocol-native.c
index 3a3a5d95e..4eab88fa3 100644
--- a/src/modules/module-client-node/protocol-native.c
+++ b/src/modules/module-client-node/protocol-native.c
@@ -1062,9 +1062,7 @@ static int client_node_demarshal_port_buffers(void *object, const struct pw_prot
 	for (i = 0; i < n_buffers; i++) {
 		struct spa_buffer *buf = buffers[i] = alloca(sizeof(struct spa_buffer));
 
-		buf->n_metas = 0;
-		buf->metas = NULL;
-
+		spa_zero(*buf);
 		if (spa_pod_parser_get(&prs,
 					SPA_POD_Int(&buf->n_datas), NULL) < 0)
 			return -EINVAL;