diff --git a/src/borg/constants.py b/src/borg/constants.py
index 0aac942a9..6b9544a31 100644
--- a/src/borg/constants.py
+++ b/src/borg/constants.py
@@ -104,6 +104,27 @@ DASHES = '-' * 78
 PBKDF2_ITERATIONS = 100000
 
 
+class KeyBlobStorage:
+    NO_STORAGE = 'no_storage'
+    KEYFILE = 'keyfile'
+    REPO = 'repository'
+
+
+class KeyType:
+    KEYFILE = 0x00
+    # repos with PASSPHRASE mode could not be created any more since borg 1.0, see #97.
+    # in borg 1.3 all of its code and also the "borg key migrate-to-repokey" command was removed.
+    # if you still need to, you can use "borg key migrate-to-repokey" with borg 1.0, 1.1 and 1.2.
+    # Nowadays, we just dispatch this to RepoKey and assume the passphrase was migrated to a repokey.
+    PASSPHRASE = 0x01  # legacy, attic and borg < 1.0
+    PLAINTEXT = 0x02
+    REPO = 0x03
+    BLAKE2KEYFILE = 0x04
+    BLAKE2REPO = 0x05
+    BLAKE2AUTHENTICATED = 0x06
+    AUTHENTICATED = 0x07
+
+
 REPOSITORY_README = """This is a Borg Backup repository.
 See https://borgbackup.readthedocs.io/
 """
diff --git a/src/borg/crypto/key.py b/src/borg/crypto/key.py
index ab86df528..59be43a85 100644
--- a/src/borg/crypto/key.py
+++ b/src/borg/crypto/key.py
@@ -76,23 +76,6 @@ class TAMUnsupportedSuiteError(IntegrityError):
     traceback = False
 
 
-class KeyBlobStorage:
-    NO_STORAGE = 'no_storage'
-    KEYFILE = 'keyfile'
-    REPO = 'repository'
-
-
-class KeyType:
-    KEYFILE = 0x00
-    PASSPHRASE = 0x01  # legacy, attic and borg < 1.0
-    PLAINTEXT = 0x02
-    REPO = 0x03
-    BLAKE2KEYFILE = 0x04
-    BLAKE2REPO = 0x05
-    BLAKE2AUTHENTICATED = 0x06
-    AUTHENTICATED = 0x07
-
-
 def key_creator(repository, args):
     for key in AVAILABLE_KEY_TYPES:
         if key.ARG_NAME == args.encryption:
@@ -108,8 +91,8 @@ def key_argument_names():
 
 def identify_key(manifest_data):
     key_type = manifest_data[0]
-    if key_type == PassphraseKey.TYPE:
-        return RepoKey  # see comment in PassphraseKey class.
+    if key_type == KeyType.PASSPHRASE:  # legacy, see comment in KeyType class.
+        return RepoKey
 
     for key in AVAILABLE_KEY_TYPES:
         if key.TYPE == key_type:
@@ -642,15 +625,6 @@ class FlexiKey(ID_HMAC_SHA_256, FlexiKeyBase):
             target.save_key(b'')  # save empty key (no new api at remote repo necessary)
 
 
-class PassphraseKey:
-    # this is only a stub, repos with this mode could not be created any more since borg 1.0, see #97.
-    # in borg 1.3 all of its code and also the "borg key migrate-to-repokey" command was removed.
-    # if you still need to, you can use "borg key migrate-to-repokey" with borg 1.0, 1.1 and 1.2.
-    # Nowadays, we just dispatch this to RepoKey and assume the passphrase was migrated to a repokey.
-    TYPE = KeyType.PASSPHRASE
-    NAME = 'passphrase'
-
-
 class KeyfileKey(FlexiKey):
     TYPE = KeyType.KEYFILE
     NAME = 'key file'