diff --git a/test/test_file.py b/test/test_file.py
index 6234e2a..27166fe 100644
--- a/test/test_file.py
+++ b/test/test_file.py
@@ -15,6 +15,7 @@ tm_cost = t2-t1
 
 log_f = open("1.log","wb")
 log_f.write(words.encode('utf-8'))
+log_f.close()
 
 print 'cost',tm_cost
 print 'speed' , len(content)/tm_cost, " bytes/second"