diff --git a/src/modules/module-protocol-native/connection.c b/src/modules/module-protocol-native/connection.c
index 15c739428..584ca9c17 100644
--- a/src/modules/module-protocol-native/connection.c
+++ b/src/modules/module-protocol-native/connection.c
@@ -144,6 +144,8 @@ static void *connection_ensure_size(struct pw_protocol_native_connection *conn,
 		if (np == NULL) {
 			res = -errno;
 			free(buf->buffer_data);
+			buf->buffer_data = NULL;
+			buf->buffer_size = 0;
 			buf->buffer_maxsize = 0;
 			spa_hook_list_call(&conn->listener_list,
 					struct pw_protocol_native_connection_events,