diff --git a/cryptography/exceptions.py b/cryptography/exceptions.py
index f2a731f..8b28667 100644
--- a/cryptography/exceptions.py
+++ b/cryptography/exceptions.py
@@ -20,5 +20,5 @@
     pass
 
 
-class NotFinalized(Exception):
+class NotYetFinalized(Exception):
     pass
diff --git a/cryptography/hazmat/primitives/ciphers/base.py b/cryptography/hazmat/primitives/ciphers/base.py
index 5a4e785..3a27030 100644
--- a/cryptography/hazmat/primitives/ciphers/base.py
+++ b/cryptography/hazmat/primitives/ciphers/base.py
@@ -14,7 +14,7 @@
 from __future__ import absolute_import, division, print_function
 
 from cryptography import utils
-from cryptography.exceptions import AlreadyFinalized, NotFinalized
+from cryptography.exceptions import AlreadyFinalized, NotYetFinalized
 from cryptography.hazmat.primitives import interfaces
 
 
@@ -87,6 +87,6 @@
     @property
     def tag(self):
         if self._ctx is not None:
-            raise NotFinalized("You must finalize encryption before "
-                               "getting the tag")
+            raise NotYetFinalized("You must finalize encryption before "
+                                  "getting the tag")
         return self._tag
diff --git a/tests/hazmat/primitives/utils.py b/tests/hazmat/primitives/utils.py
index 839ff82..9845555 100644
--- a/tests/hazmat/primitives/utils.py
+++ b/tests/hazmat/primitives/utils.py
@@ -7,7 +7,7 @@
 from cryptography.hazmat.primitives import hashes, hmac
 from cryptography.hazmat.primitives.ciphers import Cipher
 from cryptography.exceptions import (
-    AlreadyFinalized, NotFinalized,
+    AlreadyFinalized, NotYetFinalized,
 )
 
 from ...utils import load_vectors_from_file
@@ -333,7 +333,7 @@
     )
     encryptor = cipher.encryptor()
     encryptor.update(b"a" * 16)
-    with pytest.raises(NotFinalized):
+    with pytest.raises(NotYetFinalized):
         encryptor.tag
     encryptor.finalize()
     with pytest.raises(AlreadyFinalized):