diff --git a/nova/api/openstack/compute/legacy_v2/servers.py b/nova/api/openstack/compute/legacy_v2/servers.py
index 3b339de9d2..e5eecd64be 100644
--- a/nova/api/openstack/compute/legacy_v2/servers.py
+++ b/nova/api/openstack/compute/legacy_v2/servers.py
@@ -364,6 +364,11 @@ class Controller(wsgi.Controller):
                            '|[A-Za-z0-9+\/]{3}=)?$')
 
     def _decode_base64(self, data):
+        if isinstance(data, six.binary_type) and hasattr(data, "decode"):
+            try:
+                data = data.decode("utf-8")
+            except UnicodeDecodeError:
+                return None
         data = re.sub(r'\s', '', data)
         if not self.B64_REGEX.match(data):
             return None
diff --git a/nova/tests/unit/api/openstack/compute/legacy_v2/test_servers.py b/nova/tests/unit/api/openstack/compute/legacy_v2/test_servers.py
index 39e70d1bba..4c706cbac4 100644
--- a/nova/tests/unit/api/openstack/compute/legacy_v2/test_servers.py
+++ b/nova/tests/unit/api/openstack/compute/legacy_v2/test_servers.py
@@ -126,18 +126,18 @@ class Base64ValidationTest(test.TestCase):
         self.controller = servers.Controller(self.ext_mgr)
 
     def test_decode_base64(self):
-        value = "A random string"
+        value = b"A random string"
         result = self.controller._decode_base64(base64.b64encode(value))
         self.assertEqual(value, result)
 
     def test_decode_base64_binary(self):
-        value = "\x00\x12\x75\x99"
+        value = b"\x00\x12\x75\x99"
         result = self.controller._decode_base64(base64.b64encode(value))
         self.assertEqual(value, result)
 
     def test_decode_base64_whitespace(self):
-        value = "A random string"
-        encoded = base64.b64encode(value)
+        value = b"A random string"
+        encoded = base64.b64encode(value).decode("ascii")
         white = "\n \n%s\t%s\n" % (encoded[:2], encoded[2:])
         result = self.controller._decode_base64(white)
         self.assertEqual(value, result)
@@ -148,8 +148,8 @@ class Base64ValidationTest(test.TestCase):
         self.assertIsNone(result)
 
     def test_decode_base64_illegal_bytes(self):
-        value = "A random string"
-        encoded = base64.b64encode(value)
+        value = b"A random string"
+        encoded = base64.b64encode(value).decode("ascii")
         white = ">\x01%s*%s()" % (encoded[:2], encoded[2:])
         result = self.controller._decode_base64(white)
         self.assertIsNone(result)
diff --git a/tests-py3.txt b/tests-py3.txt
index f1657fc0c1..8a33317806 100644
--- a/tests-py3.txt
+++ b/tests-py3.txt
@@ -14,7 +14,6 @@ nova.tests.unit.api.openstack.compute.legacy_v2.test_extensions.ExtensionControl
 nova.tests.unit.api.openstack.compute.legacy_v2.test_extensions.ExtensionManagerTest
 nova.tests.unit.api.openstack.compute.legacy_v2.test_extensions.RequestExtensionTest
 nova.tests.unit.api.openstack.compute.legacy_v2.test_extensions.ResourceExtensionTest
-nova.tests.unit.api.openstack.compute.legacy_v2.test_servers.Base64ValidationTest
 nova.tests.unit.api.openstack.compute.legacy_v2.test_servers.ServersControllerCreateTest
 nova.tests.unit.api.openstack.compute.legacy_v2.test_servers.ServersControllerCreateTestWithMock
 nova.tests.unit.api.openstack.compute.legacy_v2.test_servers.ServersControllerRebuildInstanceTest