diff --git a/README.rst b/README.rst
index dba6888..d4fd3e2 100644
--- a/README.rst
+++ b/README.rst
@@ -54,6 +54,14 @@ There are some examples in the folder *examples*.
     $ cd stegano/examples
 
 
+Running the tests
+-----------------
+
+.. code:: bash
+
+    $ python -m unittest discover -v
+
+
 Turorial
 --------
 
diff --git a/stegano/slsb.py b/stegano/slsb.py
index bcb81c1..ae2b42b 100755
--- a/stegano/slsb.py
+++ b/stegano/slsb.py
@@ -81,6 +81,7 @@ def hide(input_image_file, message):
 
             index += 3
 
+    img.close()
     return encoded
 
 def reveal(input_image_file):
@@ -110,7 +111,9 @@ def reveal(input_image_file):
                             pass
 
             if len(bitab)-len(str(limit))-1 == limit :
+                img.close()
                 return "".join(bitab)[len(str(limit))+1:]
+    img.close()
     return ""
 
 def write(image, output_image_file):
@@ -121,6 +124,8 @@ def write(image, output_image_file):
     except Exception as e:
         # If hide() returns an error (Too long message).
         print(e)
+    finally:
+        image.close()
 
 if __name__ == '__main__':
     # Point of entry in execution mode.
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_slsb.py b/tests/test_slsb.py
new file mode 100644
index 0000000..0c7c63a
--- /dev/null
+++ b/tests/test_slsb.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python
+#-*- coding: utf-8 -*-
+
+# Stéganô - Stéganô is a basic Python Steganography module.
+# Copyright (C) 2010-2016  Cédric Bonhomme - https://www.cedricbonhomme.org
+#
+# For more information : https://github.com/cedricbonhomme/Stegano
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.1 $"
+__date__ = "$Date: 2016/04/12 $"
+__license__ = "GPLv3"
+
+import os
+import unittest
+
+from stegano import slsb
+
+class TestSLSB(unittest.TestCase):
+
+    def test_hide_empty_message(self):
+        """
+        Test hiding the empty string.
+        """
+        secret = slsb.hide("./examples/pictures/Lenna.png", "")
+        secret.save("./image.png")
+
+        clear_message = slsb.reveal("./image.png")
+
+        self.assertEqual("", clear_message)
+
+    def test_hide_and_reveal(self):
+        messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
+
+        for message in messages_to_hide:
+            secret = slsb.hide("./examples/pictures/Lenna.png", message)
+            secret.save("./image.png")
+
+            clear_message = slsb.reveal("./image.png")
+
+            self.assertEqual(message, clear_message)
+
+    def test_with_long_message(self):
+        with open("./examples/lorem_ipsum.txt") as f:
+            message = f.read()
+        secret = slsb.hide("./examples/pictures/Lenna.png", message)
+
+    def test_with_too_long_message(self):
+        with open("./examples/lorem_ipsum.txt") as f:
+            message = f.read()
+        message += message*2
+        with self.assertRaises(Exception):
+            slsb.hide("./examples/pictures/Lenna.png", message)
+
+    def tearDown(self):
+        try:
+            os.unlink("./image.png")
+        except:
+            pass
+
+
+if __name__ == '__main__':
+    unittest.main()