diff --git a/certbot/interfaces.py b/certbot/interfaces.py
index 19d9f0c07..37835462e 100644
--- a/certbot/interfaces.py
+++ b/certbot/interfaces.py
@@ -201,7 +201,7 @@ class IConfig(zope.interface.Interface):
         "Email used for registration and recovery contact.")
     rsa_key_size = zope.interface.Attribute("Size of the RSA key.")
     must_staple = zope.interface.Attribute(
-        "Adds the OCSP Must Staple extension to the certificate."
+        "Adds the OCSP Must Staple extension to the certificate. "
         "Autoconfigures OCSP Stapling for supported setups "
         "(Apache version >= 2.3.3 ).")