diff --git a/server/signserver/dsgn_resp.go b/server/signserver/dsgn_resp.go
index 091abc687..cbad6405c 100644
--- a/server/signserver/dsgn_resp.go
+++ b/server/signserver/dsgn_resp.go
@@ -120,7 +120,12 @@ func (s *Session) makeSignInResp(uid int) []byte {
 	bf.WriteUint16(0x0001)
 	bf.WriteUint16(0x4E20)
 	ps.Uint16(bf, "", false) // unk ipv4
-	bf.WriteUint32(uint32(returnExpiry.Unix()))
+	if returnExpiry.Before(time.Now()) {
+		// Hack to make Return work while having a non-adjusted expiry
+		bf.WriteUint32(0)
+	} else {
+		bf.WriteUint32(uint32(returnExpiry.Unix()))
+	}
 	bf.WriteUint32(0x00000000)
 	bf.WriteUint32(0x0A5197DF) // unk id