diff --git a/alignment/sgns_vi_l2normalize.py b/alignment/sgns_vi_l2normalize.py
index d83f9f0..962bedf 100644
--- a/alignment/sgns_vi_l2normalize.py
+++ b/alignment/sgns_vi_l2normalize.py
@@ -7,6 +7,7 @@
 import gensim
 from gensim.models.word2vec import PathLineSentences
 from gensim.models import Word2Vec
+import numpy as np
 
 
 def main():