diff --git a/main.go b/main.go
index 7c45350..318a7bd 100644
--- a/main.go
+++ b/main.go
@@ -388,7 +388,7 @@ func main() {
 
 	// Update fast token if a new one is received or expiry time is reduced.
 	if (client.Fast.Token != "" && client.Fast.Token != fast.Token) ||
-		client.Fast.Expiry.Before(fast.Expiry) {
+		(client.Fast.Expiry.Before(fast.Expiry) && !client.Fast.Expiry.IsZero()) {
 		fast.Token = client.Fast.Token
 		fast.Mechanism = client.Fast.Mechanism
 		fast.Expiry = client.Fast.Expiry