diff --git a/letsencrypt/client/configuration.py b/letsencrypt/client/configuration.py
new file mode 100644
index 000000000..a39bf4732
--- /dev/null
+++ b/letsencrypt/client/configuration.py
@@ -0,0 +1,35 @@
+"""Let's Encrypt user-supplied configuration."""
+import zope.interface
+
+from letsencrypt.client import interfaces
+
+
+class NamespaceConfig(object):
+    """Configuration wrapper around `argparse.Namespace`."""
+    zope.interface.implements(interfaces.IConfig)
+
+    def __init__(self, namespace):
+        self.namespace = namespace
+
+    def __getattr__(self, name):
+        return getattr(self.namespace, name)
+
+    @property
+    def temp_checkpoint_dir(self):
+        return os.path.join(
+            self.namespace.work_dir, constants.TEMP_CHECKPOINT_DIR_NAME)
+
+    @property
+    def in_progress_dir(self):
+        return os.path.join(
+            self.namespace.work_dir, constants.IN_PROGRESS_DIR_NAME)
+
+    @property
+    def cert_key_backup(self):
+        return os.path.join(
+            self.namespace.work_dir, constants.CERT_KEY_BACKUP_DIR_NAME)
+
+    @property
+    def rev_tokens_dir(self):
+        return os.path.join(
+            self.namespace.work_dir, constants.REV_TOKENS_DIR_NAME)
diff --git a/letsencrypt/client/constants.py b/letsencrypt/client/constants.py
index d07737ac7..3414bce74 100644
--- a/letsencrypt/client/constants.py
+++ b/letsencrypt/client/constants.py
@@ -47,3 +47,19 @@ APACHE_REWRITE_HTTPS_ARGS = [
 
 DVSNI_DOMAIN_SUFFIX = ".acme.invalid"
 """Suffix appended to domains in DVSNI validation."""
+
+
+TEMP_CHECKPOINT_DIR_NAME = "temp_checkpoint"
+"""Temporary checkpoint directory (relative to IConfig.work_dir)."""
+
+IN_PROGRESS_DIR_NAME = "IN_PROGRESS"
+"""Directory used before a permanent checkpoint is finalized (relative to
+IConfig.work_dir)."""
+
+CERT_KEY_BACKUP_DIR_NAME = "keys-certs"
+"""Directory where all certificates and keys are stored (relative to
+IConfig.work_dir. Used for easy revocation."""
+
+REV_TOKENS_DIR_NAME = "revocation_tokens"
+"""Directory where all revocation tokens are saved (relative to
+IConfig.work_dir)."""
diff --git a/letsencrypt/client/interfaces.py b/letsencrypt/client/interfaces.py
index c4f28afdb..f9c614614 100644
--- a/letsencrypt/client/interfaces.py
+++ b/letsencrypt/client/interfaces.py
@@ -60,7 +60,7 @@ class IChallenge(zope.interface.Interface):
 
 
 class IConfig(zope.interface.Interface):
-    """Marker interface for Let's Encrypt config."""
+    """Let's Encrypt uesr-supplied configuration."""
 
 
 class IInstaller(zope.interface.Interface):
diff --git a/letsencrypt/scripts/main.py b/letsencrypt/scripts/main.py
index a6a12f725..62e007128 100755
--- a/letsencrypt/scripts/main.py
+++ b/letsencrypt/scripts/main.py
@@ -11,10 +11,11 @@ import sys
 
 import confargparse
 import zope.component
-import zope.interface
 
 import letsencrypt
 
+from letsencrypt.client import constants
+from letsencrypt.client import configuration
 from letsencrypt.client import client
 from letsencrypt.client import display
 from letsencrypt.client import errors
@@ -60,17 +61,6 @@ def create_parser():
         help="Working directory.")
     add("--backup-dir", default="/var/lib/letsencrypt/backups",
         help="Configuration backups directory.")
-    add("--temp-checkpoint-dir",
-        default="/var/lib/letsencrypt/temp_checkpoint",
-        help="Temporary checkpoint directory.")
-    add("--in-progress-dir",
-        default="/var/lib/letsencrypt/backups/IN_PROGRESS",
-        help="Directory used before a permanent checkpoint is finalized")
-    add("--cert-key-backup", default="/var/lib/letsencrypt/keys-certs",
-        help="Directory where all certificates and keys are stored. "
-             "Used for easy revocation.")
-    add("--rev-tokens-dir", default="/var/lib/letsencrypt/revocation_tokens",
-        help="Directory where all revocation tokens are saved.")
     add("--key-dir", default="/etc/letsencrypt/keys", help="Keys storage.")
     add("--cert-dir", default="/etc/letsencrypt/certs",
         help="Certificates storage.")
@@ -96,12 +86,12 @@ def create_parser():
 
     return parser
 
+
 def main():  # pylint: disable=too-many-branches
     """Command line argument parsing and main script execution."""
-
     # note: arg parser internally handles --help (and exits afterwards)
-    config = create_parser().parse_args()
-    zope.interface.directlyProvides(config, interfaces.IConfig)
+    args = create_parser().parse_args()
+    config = configuration.NamespaceConfig(args)
 
     # note: check is done after arg parsing as --help should work w/o root also.
     if not os.geteuid() == 0: