diff --git a/spa/plugins/alsa/acp/acp.c b/spa/plugins/alsa/acp/acp.c
index 0d773ef8a..f95440737 100644
--- a/spa/plugins/alsa/acp/acp.c
+++ b/spa/plugins/alsa/acp/acp.c
@@ -247,7 +247,7 @@ static void init_device(pa_card *impl, pa_alsa_device *dev, pa_alsa_direction_t
 		if ((snd_use_case_get(impl->ucm.ucm_mgr, "_alibpref", &alibpref) != 0))
 			alibpref = NULL;
 		if (alibpref == NULL)
-			alibpref = spa_aprintf("_ucm%04X.", impl->card.index);
+			alibpref = strdup("_ucm");
 		if (alibpref != NULL) {
 			char **d;
 			for (d = m->device_strings; *d; d++) {