diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 1c4139942f..dac5e9285c 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -17,6 +17,15 @@ Changelog
 .. Release notes for existing releases are MUTABLE! If there is something that
    was missed or can be improved, feel free to change it!
 
+[unreleased]
+------------
+
+Fixed
+~~~~~
+
+* Python 3 issue of Verification component
+* Docker README file
+
 [1.4.0] - 2019-02-04
 --------------------
 
diff --git a/rally/verification/manager.py b/rally/verification/manager.py
index de771da6ce..881448d103 100644
--- a/rally/verification/manager.py
+++ b/rally/verification/manager.py
@@ -191,7 +191,8 @@ class VerifierManager(plugin.Plugin):
     def _clone(self):
         """Clone a repo and switch to a certain version."""
         source = self.verifier.source or self._meta_get("default_repo")
-        if not URL_RE.match(source) and not os.path.exists(source):
+        if not source or (
+                not URL_RE.match(source) and not os.path.exists(source)):
             raise exceptions.RallyException("Source path '%s' is not valid."
                                             % source)
 
diff --git a/rally/verification/utils.py b/rally/verification/utils.py
index cdf823afdb..7a0639f21f 100644
--- a/rally/verification/utils.py
+++ b/rally/verification/utils.py
@@ -58,8 +58,9 @@ def check_output(*args, **kwargs):
         LOG.error("Error output: '%s'" % encodeutils.safe_decode(exc.output))
         raise
 
+    output = encodeutils.safe_decode(output)
     if output and debug_output:
-        LOG.debug("Subprocess output: '%s'" % encodeutils.safe_decode(output))
+        LOG.debug("Subprocess output: '%s'" % output)
 
     return output
 
diff --git a/tests/unit/verification/test_utils.py b/tests/unit/verification/test_utils.py
index e113120306..ae388b1531 100644
--- a/tests/unit/verification/test_utils.py
+++ b/tests/unit/verification/test_utils.py
@@ -40,9 +40,11 @@ class UtilsTestCase(test.TestCase):
     def test_check_output(self, mock_check_output, mock_log,
                           mock_encodeutils):
 
-        self.assertEqual(mock_check_output.return_value,
+        self.assertEqual(mock_encodeutils.safe_decode.return_value,
                          utils.check_output())
         self.assertFalse(mock_log.error.called)
+        mock_encodeutils.safe_decode.assert_called_once_with(
+            mock_check_output.return_value)
 
         mock_check_output.side_effect = subprocess.CalledProcessError(1, None)
         self.assertRaises(subprocess.CalledProcessError, utils.check_output)