diff --git a/noise/noise_protocol.py b/noise/noise_protocol.py
index 060e44e..3eb065e 100644
--- a/noise/noise_protocol.py
+++ b/noise/noise_protocol.py
@@ -27,13 +27,16 @@ class NoiseProtocol(object):
         self.psks = None
         self.is_psk_handshake = any([modifier.startswith('psk') for modifier in self.pattern_modifiers])
 
+        # Preinitialized
         self.dh_fn = mappings['dh']()
         self.hash_fn = mappings['hash']()
-        self.cipher_fn = mappings['cipher']
-        self.keypair_fn = mappings['keypair']
         self.hmac = partial(backend.hmac, algorithm=self.hash_fn.fn)
         self.hkdf = partial(backend.hkdf, hmac_hash_fn=self.hmac)
 
+        # Initialized where needed
+        self.cipher_class = mappings['cipher']
+        self.keypair_class = mappings['keypair']
+
         self.prologue = None
         self.initiator = None
         self.handshake_hash = None
@@ -60,7 +63,7 @@ class NoiseProtocol(object):
         del self.initiator
         del self.dh_fn
         del self.hash_fn
-        del self.keypair_fn
+        del self.keypair_class
 
     def validate(self):
         if self.is_psk_handshake:
diff --git a/noise/state.py b/noise/state.py
index 63e53b6..312550f 100644
--- a/noise/state.py
+++ b/noise/state.py
@@ -16,7 +16,7 @@ class CipherState(object):
     def __init__(self, noise_protocol):
         self.k = Empty()
         self.n = None
-        self.cipher = noise_protocol.cipher_fn()
+        self.cipher = noise_protocol.cipher_class()
 
     def initialize_key(self, key):
         """
@@ -363,7 +363,7 @@ class HandshakeState(object):
         for token in message_pattern:
             if token == TOKEN_E:
                 # Sets re to the next DHLEN bytes from the message. Calls MixHash(re.public_key).
-                self.re = self.noise_protocol.keypair_fn.from_public_bytes(bytes(message[:dhlen]))
+                self.re = self.noise_protocol.keypair_class.from_public_bytes(bytes(message[:dhlen]))
                 message = message[dhlen:]
                 self.symmetric_state.mix_hash(self.re.public_bytes)
                 if self.noise_protocol.is_psk_handshake:
@@ -378,7 +378,9 @@ class HandshakeState(object):
                 else:
                     temp = bytes(message[:dhlen])
                     message = message[dhlen:]
-                self.rs = self.noise_protocol.keypair_fn.from_public_bytes(self.symmetric_state.decrypt_and_hash(temp))
+                self.rs = self.noise_protocol.keypair_class.from_public_bytes(
+                    self.symmetric_state.decrypt_and_hash(temp)
+                )
 
             elif token == TOKEN_EE:
                 # Calls MixKey(DH(e, re)).