diff --git a/core/admin/mailu/models.py b/core/admin/mailu/models.py
index b5ba29c0..a86e005f 100644
--- a/core/admin/mailu/models.py
+++ b/core/admin/mailu/models.py
@@ -507,13 +507,13 @@ class User(Base, Email):
         if cls._ctx:
             return cls._ctx
 
-        schemes = passlib.registry.list_crypt_handlers()
-        # scrypt throws a warning if the native wheels aren't found
-        schemes.remove('scrypt')
-        # we can't leave plaintext schemes as they will be misidentified
-        for scheme in schemes:
-            if scheme.endswith('plaintext'):
-                schemes.remove(scheme)
+        # compile schemes
+        # - scrypt throws a warning if the native wheels aren't found
+        # - we can't leave plaintext schemes as they will be misidentified
+        schemes = [
+            scheme for scheme in passlib.registry.list_crypt_handlers()
+            if not (scheme == 'scrypt' or scheme.endswith('plaintext'))
+        ]
         cls._ctx = passlib.context.CryptContext(
             schemes=schemes,
             default='bcrypt_sha256',