diff --git a/letsencrypt/client/crypto_util.py b/letsencrypt/client/crypto_util.py
index b7644aecc..feff99abe 100644
--- a/letsencrypt/client/crypto_util.py
+++ b/letsencrypt/client/crypto_util.py
@@ -255,5 +255,6 @@ def get_cert_info(filename):
 
 
 def b64_cert_to_pem(b64_der_cert):
+    """Convert JOSE Base-64 encoded DER cert to PEM."""
     return M2Crypto.X509.load_cert_der_string(
         le_util.jose_b64decode(b64_der_cert)).as_pem()
diff --git a/letsencrypt/client/display.py b/letsencrypt/client/display.py
index 30f9deaf7..2c379fef8 100644
--- a/letsencrypt/client/display.py
+++ b/letsencrypt/client/display.py
@@ -1,3 +1,4 @@
+"""Lets Encrypt display."""
 import textwrap
 
 import dialog
@@ -30,6 +31,8 @@ class CommonDisplayMixin(object):  # pylint: disable=too-few-public-methods
 
 
 class NcursesDisplay(CommonDisplayMixin):
+    """Ncurses-based display."""
+
     zope.interface.implements(interfaces.IDisplay)
 
     def __init__(self, width=WIDTH, height=HEIGHT):
@@ -107,6 +110,8 @@ class NcursesDisplay(CommonDisplayMixin):
 
 
 class FileDisplay(CommonDisplayMixin):
+    """File-based display."""
+
     zope.interface.implements(interfaces.IDisplay)
 
     def __init__(self, outfile):