use interfaces rather than concrete types
diff --git a/rackspace/db/v1/users/requests.go b/rackspace/db/v1/users/requests.go
index aab7e41..74e47ab 100644
--- a/rackspace/db/v1/users/requests.go
+++ b/rackspace/db/v1/users/requests.go
@@ -29,7 +29,7 @@
ChangePassword(client, "instance_id", opts)
*/
-func ChangePassword(client *gophercloud.ServiceClient, instanceID string, opts os.BatchCreateOpts) UpdatePasswordsResult {
+func ChangePassword(client *gophercloud.ServiceClient, instanceID string, opts os.CreateOptsBuilder) UpdatePasswordsResult {
var res UpdatePasswordsResult
reqBody, err := opts.ToUserCreateMap()
@@ -142,7 +142,7 @@
GrantAccess(client, "instance_id", "user_name", opts)
*/
-func GrantAccess(client *gophercloud.ServiceClient, instanceID, userName string, opts db.BatchCreateOpts) GrantAccessResult {
+func GrantAccess(client *gophercloud.ServiceClient, instanceID, userName string, opts db.CreateOptsBuilder) GrantAccessResult {
var res GrantAccessResult
reqBody, err := opts.ToDBCreateMap()