diff --git a/custompuppet.go b/custompuppet.go
index 8ea2593d..b1aa2176 100644
--- a/custompuppet.go
+++ b/custompuppet.go
@@ -22,6 +22,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"strings"
 
 	"maunium.net/go/mautrix"
 	"maunium.net/go/mautrix/appservice"
@@ -86,6 +87,9 @@ func (user *User) loginWithSharedSecret() error {
 	if loginSecret == "appservice" {
 		client.AccessToken = user.bridge.AS.Registration.AppToken
 		req.Type = mautrix.AuthTypeAppservice
+	} else if strings.HasPrefix(loginSecret, "as_token:") {
+		client.AccessToken = loginSecret[9:]
+		req.Type = mautrix.AuthTypeAppservice
 	} else {
 		mac := hmac.New(sha512.New, []byte(loginSecret))
 		mac.Write([]byte(user.MXID))