OID validation
diff --git a/tests/test_x509_ext.py b/tests/test_x509_ext.py
index 8f46936..751de08 100644
--- a/tests/test_x509_ext.py
+++ b/tests/test_x509_ext.py
@@ -18,7 +18,8 @@
 )
 from cryptography.hazmat.primitives.asymmetric import ec
 from cryptography.x509.oid import (
-    AuthorityInformationAccessOID, ExtendedKeyUsageOID, ExtensionOID, NameOID
+    AuthorityInformationAccessOID, ExtendedKeyUsageOID,
+    ExtensionOID, NameOID
 )
 
 from .hazmat.primitives.test_ec import _skip_curve_unsupported
@@ -603,8 +604,14 @@
     def test_authority_cert_serial_number_not_integer(self):
         dirname = x509.DirectoryName(
             x509.Name([
-                x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value1'),
-                x509.NameAttribute(x509.ObjectIdentifier('oid2'), u'value2'),
+                x509.NameAttribute(
+                    x509.ObjectIdentifier('2.999.1'),
+                    u'value1'
+                ),
+                x509.NameAttribute(
+                    x509.ObjectIdentifier('2.999.2'),
+                    u'value2'
+                ),
             ])
         )
         with pytest.raises(TypeError):
@@ -617,8 +624,14 @@
     def test_authority_issuer_not_none_serial_none(self):
         dirname = x509.DirectoryName(
             x509.Name([
-                x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value1'),
-                x509.NameAttribute(x509.ObjectIdentifier('oid2'), u'value2'),
+                x509.NameAttribute(
+                    x509.ObjectIdentifier('2.999.1'),
+                    u'value1'
+                ),
+                x509.NameAttribute(
+                    x509.ObjectIdentifier('2.999.2'),
+                    u'value2'
+                ),
             ])
         )
         with pytest.raises(ValueError):
@@ -1166,10 +1179,10 @@
 
     def test_eq(self):
         name = x509.Name([
-            x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value1')
+            x509.NameAttribute(x509.ObjectIdentifier('2.999.1'), u'value1')
         ])
         name2 = x509.Name([
-            x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value1')
+            x509.NameAttribute(x509.ObjectIdentifier('2.999.1'), u'value1')
         ])
         gn = x509.DirectoryName(x509.Name([name]))
         gn2 = x509.DirectoryName(x509.Name([name2]))
@@ -1177,10 +1190,10 @@
 
     def test_ne(self):
         name = x509.Name([
-            x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value1')
+            x509.NameAttribute(x509.ObjectIdentifier('2.999.1'), u'value1')
         ])
         name2 = x509.Name([
-            x509.NameAttribute(x509.ObjectIdentifier('oid'), u'value2')
+            x509.NameAttribute(x509.ObjectIdentifier('2.999.2'), u'value2')
         ])
         gn = x509.DirectoryName(x509.Name([name]))
         gn2 = x509.DirectoryName(x509.Name([name2]))