diff --git a/letsencrypt/acme/other.py b/letsencrypt/acme/other.py
index 63955ae2f..7520bdde2 100644
--- a/letsencrypt/acme/other.py
+++ b/letsencrypt/acme/other.py
@@ -10,8 +10,6 @@ import zope.interface
 from letsencrypt.acme import interfaces
 from letsencrypt.acme import jose
 
-from letsencrypt.client import CONFIG
-
 
 class Signature(object):
     """ACME signature.
@@ -28,7 +26,8 @@ class Signature(object):
     """
     zope.interface.implements(interfaces.IJSONSerializable)
 
-    NONCE_LEN = CONFIG.NONCE_SIZE
+    NONCE_LEN = 16
+    """Size of nonce in bytes, as specified in the ACME protocol."""
 
     def __init__(self, alg, sig, nonce, jwk):
         self.alg = alg
diff --git a/letsencrypt/client/CONFIG.py b/letsencrypt/client/CONFIG.py
index 5a07a4aa2..57e894ab2 100644
--- a/letsencrypt/client/CONFIG.py
+++ b/letsencrypt/client/CONFIG.py
@@ -72,9 +72,6 @@ CLIENT_CHALLENGES = frozenset(
 S_SIZE = 32
 """Byte size of S"""
 
-NONCE_SIZE = 16
-"""byte size of Nonce"""
-
 # Key Sizes
 RSA_KEY_SIZE = 2048
 """Key size"""