diff --git a/src/mslookup/mdns_msg.c b/src/mslookup/mdns_msg.c
index da65fef..78ea67a 100644
--- a/src/mslookup/mdns_msg.c
+++ b/src/mslookup/mdns_msg.c
@@ -213,9 +213,9 @@
 
 	va_start(ap, value_fmt);
 	value = talloc_vasprintf(ctx, value_fmt, ap);
+	va_end(ap);
 	if (!value)
 		return NULL;
-	va_end(ap);
 	r = _osmo_mdns_record_txt_encode(ctx, key, value);
 	talloc_free(value);
 	return r;