diff --git a/tacker/conductor/conductor_server.py b/tacker/conductor/conductor_server.py
index d5b76301e..3c3747c4a 100644
--- a/tacker/conductor/conductor_server.py
+++ b/tacker/conductor/conductor_server.py
@@ -16,7 +16,6 @@
 import datetime
 import functools
 import inspect
-import io
 import os
 import shutil
 import sys
@@ -338,7 +337,8 @@ class Conductor(manager.Manager):
             for file in imported_yamls:
                 file_path = os.path.join(
                     csar_path, dir_of_parent_definition_file, file)
-                file_data = yaml.safe_load(io.open(file_path))
+                with open(file_path) as f:
+                    file_data = yaml.safe_load(f)
                 dest_file_path = os.path.abspath(file_path).split(
                     csar_path + '/')[-1]
                 file_path_and_data[dest_file_path] = yaml.dump(file_data)
@@ -356,8 +356,9 @@ class Conductor(manager.Manager):
             # This is CSAR containing a TOSCA-Metadata directory, which
             # includes the TOSCA.meta metadata file providing an entry
             # information for processing a CSAR file.
-            tosca_meta_data = yaml.safe_load(io.open(os.path.join(
-                csar_path, 'TOSCA-Metadata', 'TOSCA.meta')))
+            with open(os.path.join(
+                    csar_path, 'TOSCA-Metadata', 'TOSCA.meta')) as f:
+                tosca_meta_data = yaml.safe_load(f)
             file_path_and_data['TOSCA-Metadata/TOSCA.meta'] = yaml.dump(
                 tosca_meta_data)
             entry_defination_file = tosca_meta_data['Entry-Definitions']
@@ -371,7 +372,8 @@ class Conductor(manager.Manager):
                 os.listdir(csar_path),
                 key=lambda item: item.endswith(('yaml', '.yml')))[-1]
             src_path = os.path.join(csar_path, root_yaml_file)
-            file_data = yaml.safe_load(io.open(src_path))
+            with open(src_path) as f:
+                file_data = yaml.safe_load(f)
             file_path_and_data[root_yaml_file] = yaml.dump(file_data)
 
         return file_path_and_data
diff --git a/tacker/tests/unit/conductor/fakes.py b/tacker/tests/unit/conductor/fakes.py
index 885314eea..be9e152d0 100644
--- a/tacker/tests/unit/conductor/fakes.py
+++ b/tacker/tests/unit/conductor/fakes.py
@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import io
 import os
 from oslo_config import cfg
 import shutil
@@ -105,9 +104,9 @@ def get_expected_vnfd_data(zip_file=None):
                   'Definitions/etsi_nfv_sol001_common_types.yaml']
     file_path_and_data = {}
     for file_name in file_names:
-        with io.open(os.path.join(csar_temp_dir, file_name)) as f:
-            file_path_and_data.update({file_name: yaml.dump(yaml.safe_load(
-                f))})
+        with open(os.path.join(csar_temp_dir, file_name)) as f:
+            file_path_and_data.update({file_name: yaml.dump(
+                yaml.safe_load(f))})
 
     shutil.rmtree(csar_temp_dir)
     return file_path_and_data
diff --git a/tacker/tests/unit/nfvo/test_nfvo_plugin.py b/tacker/tests/unit/nfvo/test_nfvo_plugin.py
index 634d0dfa9..8a56b0b4a 100644
--- a/tacker/tests/unit/nfvo/test_nfvo_plugin.py
+++ b/tacker/tests/unit/nfvo/test_nfvo_plugin.py
@@ -51,8 +51,8 @@ def dummy_get_vim(*args, **kwargs):
 def _get_template(name):
     filename = os.path.abspath(os.path.join(os.path.dirname(__file__),
                                 '../../etc/samples/' + str(name)))
-    f = codecs.open(filename, encoding='utf-8', errors='strict')
-    return f.read()
+    with codecs.open(filename, encoding='utf-8', errors='strict') as f:
+        return f.read()
 
 
 class FakeDriverManager(mock.Mock):
diff --git a/tacker/tests/unit/vnfm/tosca/test_utils.py b/tacker/tests/unit/vnfm/tosca/test_utils.py
index 3cfb49131..2cc5fdc5a 100644
--- a/tacker/tests/unit/vnfm/tosca/test_utils.py
+++ b/tacker/tests/unit/vnfm/tosca/test_utils.py
@@ -27,8 +27,8 @@ def _get_template(name):
     filename = os.path.join(
         os.path.dirname(os.path.abspath(__file__)),
         "../infra_drivers/openstack/data/", name)
-    f = codecs.open(filename, encoding='utf-8', errors='strict')
-    return f.read()
+    with codecs.open(filename, encoding='utf-8', errors='strict') as f:
+        return f.read()
 
 
 class TestToscaUtils(testtools.TestCase):
diff --git a/tacker/tests/unit/vnfpkgm/fakes.py b/tacker/tests/unit/vnfpkgm/fakes.py
index 032075698..fd9e9e72b 100644
--- a/tacker/tests/unit/vnfpkgm/fakes.py
+++ b/tacker/tests/unit/vnfpkgm/fakes.py
@@ -16,7 +16,6 @@
 
 from copy import deepcopy
 import datetime
-import io
 import iso8601
 import os
 import shutil
@@ -249,9 +248,9 @@ def return_vnfd_data(csar_without_tosca_meta=False):
                       'Definitions/etsi_nfv_sol001_vnfd_types.yaml']
     file_path_and_data = {}
     for file_name in file_names:
-        with io.open(os.path.join(csar_temp_dir, file_name)) as f:
-            file_path_and_data.update({file_name: yaml.dump(yaml.safe_load(
-                f))})
+        with open(os.path.join(csar_temp_dir, file_name)) as f:
+            file_path_and_data.update({file_name: yaml.dump(
+                yaml.safe_load(f))})
 
     shutil.rmtree(csar_temp_dir)
     return file_path_and_data