diff --git a/astro_tigress/ytathena.py b/astro_tigress/ytathena.py
index dcf2afb..f44f076 100644
--- a/astro_tigress/ytathena.py
+++ b/astro_tigress/ytathena.py
@@ -9,7 +9,7 @@
 import math
 from yt.funcs import mylog
 import os
-import const
+from . import const
 
 dirpath = os.path.dirname(__file__)