diff --git a/tripleo_common/image/image_builder.py b/tripleo_common/image/image_builder.py
index 1778d6d2e..010561993 100644
--- a/tripleo_common/image/image_builder.py
+++ b/tripleo_common/image/image_builder.py
@@ -23,6 +23,11 @@ import sys
 
 from tripleo_common.image.exception import ImageBuilderException
 
+if sys.version_info[0] < 3:
+    import codecs
+    _open = open
+    open = codecs.open
+
 
 @six.add_metaclass(abc.ABCMeta)
 class ImageBuilder(object):
@@ -116,7 +121,7 @@ class DibImageBuilder(ImageBuilder):
         process = subprocess.Popen(cmd,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.STDOUT)
-        with open(log_file, 'w') as f:
+        with open(log_file, 'w', encoding='utf-8') as f:
             while True:
                 line = process.stdout.readline()
                 try:
diff --git a/tripleo_common/tests/image/test_image_builder.py b/tripleo_common/tests/image/test_image_builder.py
index b5239a343..0b661fe23 100644
--- a/tripleo_common/tests/image/test_image_builder.py
+++ b/tripleo_common/tests/image/test_image_builder.py
@@ -66,7 +66,8 @@ class TestDibImageBuilder(base.TestCase):
              'element1', 'element2'],
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT)
-        mock_open.assert_called_once_with('image/path.log', 'w')
+        mock_open.assert_called_once_with(
+            'image/path.log', 'w', encoding='utf-8')
         self.assertEqual([mock.call(u'foo\n'),
                           mock.call(u'bar\n')],
                          mock_file.write.mock_calls)
@@ -101,7 +102,8 @@ class TestDibImageBuilder(base.TestCase):
              'element1', 'element2'],
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT)
-        mock_open.assert_called_once_with('image/path.log', 'w')
+        mock_open.assert_called_once_with(
+            'image/path.log', 'w', encoding='utf-8')
         self.assertEqual([mock.call(u'error\n')],
                          mock_file.write.mock_calls)
         self.builder.logger.info.assert_has_calls([mock.call(u'error')])