diff --git a/Ext4Crypt.h b/Ext4Crypt.h
index d732e86..80838c8 100644
--- a/Ext4Crypt.h
+++ b/Ext4Crypt.h
@@ -28,8 +28,11 @@
 int e4crypt_init_user0();
 int e4crypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral);
 int e4crypt_destroy_user_key(userid_t user_id);
+int e4crypt_change_user_key(userid_t user_id, int serial,
+    const char* token, const char* old_secret, const char* new_secret);
 
-int e4crypt_unlock_user_key(userid_t user_id, int serial, const char* token);
+int e4crypt_unlock_user_key(userid_t user_id, int serial,
+    const char* token, const char* secret);
 int e4crypt_lock_user_key(userid_t user_id);
 
 int e4crypt_prepare_user_storage(const char* volume_uuid, userid_t user_id,