diff --git a/server/oauth2.go b/server/oauth2.go
index cfae5405..a82d172f 100644
--- a/server/oauth2.go
+++ b/server/oauth2.go
@@ -148,6 +148,10 @@ const (
 	responseTypeCode    = "code"     // "Regular" flow
 	responseTypeToken   = "token"    // Implicit flow for frontend apps.
 	responseTypeIDToken = "id_token" // ID Token in url fragment
+	responseTypeCodeToken = "code token" // "Regular" flow + Implicit flow
+	responseTypeCodeIDToken = "code id_token" // "Regular" flow + ID Token
+	responseTypeIDTokenToken = "id_token token" // ID Token + Implicit flow
+	responseTypeCodeIDTokenToken = "code id_token token" // "Regular" flow + ID Token + Implicit flow
 )
 
 const (