diff --git a/ess/__init__.py b/ess/__init__.py
index 2452371f75832ed8957865417adb87dd65e3ae1e..8471e65d68b71d9a0025066bc13ad1c61347e5b3 100644
--- a/ess/__init__.py
+++ b/ess/__init__.py
@@ -1,2 +1,3 @@
 import TraceWin
 import installed
+import lib_tw