diff --git a/tests/io/bytesio_ext.py b/tests/io/bytesio_ext.py
index e827d1409c178e2b4e9e96477f57992dd94513b1..e454b2fd9f2ddf735459dcaf3beb4d242fefe0e8 100644
--- a/tests/io/bytesio_ext.py
+++ b/tests/io/bytesio_ext.py
@@ -4,6 +4,10 @@ try:
 except ImportError:
     import io
 
+a = io.BytesIO(b"foobar")
+a.seek(10)
+print(a.read(10))
+
 a = io.BytesIO()
 print(a.seek(8))
 a.write(b"123")