diff --git a/pkg/sip/outbound.go b/pkg/sip/outbound.go
index 96ddd18..a9df96d 100644
--- a/pkg/sip/outbound.go
+++ b/pkg/sip/outbound.go
@@ -721,7 +721,10 @@ func (c *sipOutbound) attemptInvite(ctx context.Context, prev *sip.Request, dest
 	ctx, span := tracer.Start(ctx, "sipOutbound.attemptInvite")
 	defer span.End()
 	req := sip.NewRequest(sip.INVITE, to.Address)
-	if prev != nil {
+
+	const reuseCallID = false // FIXME some service may require the call ID to be kept between auth attempts, but Telnyx requires it to change
+
+	if reuseCallID && prev != nil {
 		if cid := prev.CallID(); cid != nil {
 			req.RemoveHeader("Call-ID")
 			req.AppendHeader(cid)