diff --git a/mistral/db/v2/sqlalchemy/models.py b/mistral/db/v2/sqlalchemy/models.py
index 5ec07aa9..500c28e6 100644
--- a/mistral/db/v2/sqlalchemy/models.py
+++ b/mistral/db/v2/sqlalchemy/models.py
@@ -282,7 +282,8 @@ def _get_hash_function_by(column_name):
     def calc_hash(context):
         d = context.current_parameters[column_name] or {}
 
-        return hashlib.sha256(json.dumps(sorted(d.items()))).hexdigest()
+        return hashlib.sha256(json.dumps(sorted(d.items())).
+                              encode('utf-8')).hexdigest()
 
     return calc_hash
 
diff --git a/mistral/engine/utils.py b/mistral/engine/utils.py
index b8c3a228..aa0d1722 100644
--- a/mistral/engine/utils.py
+++ b/mistral/engine/utils.py
@@ -26,7 +26,7 @@ LOG = logging.getLogger(__name__)
 
 
 def validate_input(definition, input, spec=None):
-    input_param_names = copy.copy((input or {}).keys())
+    input_param_names = copy.copy(list((input or {}).keys()))
     missing_param_names = []
 
     spec_input = (spec.get_input() if spec else
diff --git a/mistral/tests/base.py b/mistral/tests/base.py
index cabecaaf..dc4411d8 100644
--- a/mistral/tests/base.py
+++ b/mistral/tests/base.py
@@ -125,9 +125,11 @@ class BaseTest(base.BaseTestCase):
 
             return True
 
-        filtered_items = filter(lambda item: _matches(item, **props), items)
+        filtered_items = list(
+            filter(lambda item: _matches(item, **props), items)
+        )
 
-        found = len(list(filtered_items))
+        found = len(filtered_items)
 
         if found != count:
             LOG.info("[failed test ctx] items=%s, expected_props=%s" % (str(
diff --git a/mistral/workbook/base.py b/mistral/workbook/base.py
index 470fce80..4eff8d40 100644
--- a/mistral/workbook/base.py
+++ b/mistral/workbook/base.py
@@ -263,7 +263,7 @@ class BaseSpec(object):
 
     @staticmethod
     def _as_tuple(val):
-        return val.items()[0] if isinstance(val, dict) else (val, '')
+        return list(val.items())[0] if isinstance(val, dict) else (val, '')
 
     @staticmethod
     def _parse_cmd_and_input(cmd_str):
diff --git a/mistral/workbook/v2/workflows.py b/mistral/workbook/v2/workflows.py
index ed98daea..88d4cde5 100644
--- a/mistral/workbook/v2/workflows.py
+++ b/mistral/workbook/v2/workflows.py
@@ -13,6 +13,8 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
+import six
+
 from mistral import exceptions as exc
 from mistral import utils
 from mistral.workbook import types
@@ -60,7 +62,7 @@ class WorkflowSpec(base.BaseSpec):
 
         # Inject 'type' here, so instantiate_spec function can recognize the
         # specific subclass of TaskSpec.
-        for task in self._data.get('tasks').itervalues():
+        for task in six.itervalues(self._data.get('tasks')):
             task['type'] = self._type
 
         self._tasks = self._spec_property('tasks', tasks.TaskSpecList)
diff --git a/mistral/workflow/data_flow.py b/mistral/workflow/data_flow.py
index a0084a2d..8f6c6551 100644
--- a/mistral/workflow/data_flow.py
+++ b/mistral/workflow/data_flow.py
@@ -14,6 +14,7 @@
 #    limitations under the License.
 
 import copy
+import six
 
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -135,7 +136,7 @@ class ProxyAwareDict(dict):
             return d
 
     def iteritems(self):
-        for k, _ in super(ProxyAwareDict, self).iteritems():
+        for k, _ in six.iteritems(super(ProxyAwareDict, self)):
             yield k, self[k]
 
     def to_builtin_dict(self):
@@ -263,7 +264,7 @@ def add_workflow_variables_to_context(wf_ex, wf_spec):
 def extract_task_result_proxies_to_context(ctx):
     ctx = ProxyAwareDict(copy.deepcopy(ctx))
 
-    for task_ex_id, task_ex_name in ctx['__tasks'].iteritems():
+    for task_ex_id, task_ex_name in six.iteritems(ctx['__tasks']):
         ctx[task_ex_name] = TaskResultProxy(task_ex_id)
 
     return ctx