diff --git a/tests/70_file.py b/tests/70_file.py
index 29773db5..10eced7a 100644
--- a/tests/70_file.py
+++ b/tests/70_file.py
@@ -38,4 +38,13 @@ f()
 
 assert os.path.exists('123.bin')
 os.remove('123.bin')
-assert not os.path.exists('123.bin')
\ No newline at end of file
+assert not os.path.exists('123.bin')
+
+f = open("123.txt","w+")
+f.write("123456")
+f.seek(0)
+assert ( f.read() == "123456" )
+# cannot test seek(>0) then read() for now
+f.close()
+
+os.remove('123.txt')