diff --git a/blogtopoid/blogtopoid.py b/blogtopoid/blogtopoid.py
index 6669b62..aed3e67 100644
--- a/blogtopoid/blogtopoid.py
+++ b/blogtopoid/blogtopoid.py
@@ -249,7 +249,7 @@ class Hashstore(object):
         :param blocksize: read file in chunks of blocksize
         :return: sha256 hexdigest
         """
-        with open(filename, 'r') as afile:
+        with open(filename, 'rb') as afile:
             hasher = hashlib.sha256()
             buf = afile.read(blocksize)
             while len(buf) > 0:
diff --git a/blogtopoid/test/test_blogtopoid.py b/blogtopoid/test/test_blogtopoid.py
index 31ab324..a59df91 100644
--- a/blogtopoid/test/test_blogtopoid.py
+++ b/blogtopoid/test/test_blogtopoid.py
@@ -1,6 +1,8 @@
 from __future__ import unicode_literals
 from __future__ import absolute_import
 
+import os
+import codecs
 import hashlib
 import unittest
 
@@ -17,3 +19,50 @@ class TestTag(unittest.TestCase):
         self.assertEqual(self.tag1.colour, colour)
 
         self.assertEqual(self.tag2.colour, 'f32af7')
+
+
+class TestHashstore(unittest.TestCase):
+    def setUp(self):
+        self.hashstore = blogtopoid.Hashstore('testfile.json')
+
+    def tearDown(self):
+        try:
+            os.remove('testfile.json')
+        except OSError:  # it's ok if the file is not existant
+            pass
+
+    def test_init(self):
+        # new hashstore should be empty
+        self.assertEqual(self.hashstore.store, {})
+
+        # set something, delete obj, instanciate new hashstore
+        self.hashstore.set('testkey', 'blah')
+        del self.hashstore
+        raised = False
+        try:
+            self.hashstore
+        except AttributeError:
+            raised = True
+        self.assertTrue(raised)
+        self.hashstore = blogtopoid.Hashstore('testfile.json')
+        # new hashstore needs to have old key loaded
+        self.assertIn('testkey', self.hashstore.store)
+
+    def test_get(self):
+        self.assertIsNone(self.hashstore.get('not existant'))
+
+    def test_set(self):
+        self.assertFalse(os.path.isfile('testfile.json'))
+        self.hashstore.set('testkey', 'hashvalue')
+        self.assertTrue(os.path.isfile('testfile.json'))
+        self.assertEqual(self.hashstore.get('testkey'), 'hashvalue')
+
+    def test_hashfile(self):
+        with codecs.open('hashme.txt', 'w', 'utf-8') as afile:
+            afile.write('abc123def456')
+
+        self.assertEqual(
+            'e861b2eab679927cfa36fe256e9deb1969b0468ad0744d61064f9d188333aec6',
+            self.hashstore.hashfile('hashme.txt')
+        )
+        os.remove('hashme.txt')