diff --git a/Sketch.py b/Sketch.py
index 10791ef..f4c1310 100644
--- a/Sketch.py
+++ b/Sketch.py
@@ -1,6 +1,7 @@
 
 from numpy import *
 from openopt import SLE
+import scipy.sparse.linalg
 
 class Sketch(object):
     def __init__(self):