diff --git a/swift/common/constraints.py b/swift/common/constraints.py
index dd5c5c410f..0c23132129 100644
--- a/swift/common/constraints.py
+++ b/swift/common/constraints.py
@@ -18,12 +18,12 @@ import urllib
 from urllib import unquote
 from ConfigParser import ConfigParser, NoSectionError, NoOptionError
 
-from swift.common.utils import ismount, split_path
+from swift.common.utils import ismount, split_path, SWIFT_CONF_FILE
 from swift.common.swob import HTTPBadRequest, HTTPLengthRequired, \
     HTTPRequestEntityTooLarge, HTTPPreconditionFailed
 
 constraints_conf = ConfigParser()
-constraints_conf.read('/etc/swift/swift.conf')
+constraints_conf_exists = constraints_conf.read(SWIFT_CONF_FILE)
 
 
 def constraints_conf_int(name, default):
@@ -58,6 +58,21 @@ MAX_ACCOUNT_NAME_LENGTH = constraints_conf_int('max_account_name_length', 256)
 #: Max container name length
 MAX_CONTAINER_NAME_LENGTH = constraints_conf_int('max_container_name_length',
                                                  256)
+# A simple dictionary of all the constraints that can be specified in the
+# SWIFT_CONF_FILE.
+default_constraints = dict((
+    ('max_file_size', MAX_FILE_SIZE),
+    ('max_meta_name_length', MAX_META_NAME_LENGTH),
+    ('max_meta_value_length', MAX_META_VALUE_LENGTH),
+    ('max_meta_count', MAX_META_COUNT),
+    ('max_meta_overall_size', MAX_META_OVERALL_SIZE),
+    ('max_header_size', MAX_HEADER_SIZE),
+    ('max_object_name_length', MAX_OBJECT_NAME_LENGTH),
+    ('container_listing_limit', CONTAINER_LISTING_LIMIT),
+    ('account_listing_limit', ACCOUNT_LISTING_LIMIT),
+    ('max_account_name_length', MAX_ACCOUNT_NAME_LENGTH),
+    ('max_container_name_length', MAX_CONTAINER_NAME_LENGTH)))
+
 # Maximum slo segments in buffer
 MAX_BUFFERED_SLO_SEGMENTS = 10000
 
diff --git a/test/functional/tests.py b/test/functional/tests.py
index f222d4e9b8..6a9f78d611 100644
--- a/test/functional/tests.py
+++ b/test/functional/tests.py
@@ -25,40 +25,19 @@ import threading
 import uuid
 import unittest
 from nose import SkipTest
-from ConfigParser import ConfigParser
 
 from test import get_config
 from test.functional.swift_test_client import Account, Connection, File, \
     ResponseError
-from swift.common.constraints import MAX_FILE_SIZE, MAX_META_NAME_LENGTH, \
-    MAX_META_VALUE_LENGTH, MAX_META_COUNT, MAX_META_OVERALL_SIZE, \
-    MAX_OBJECT_NAME_LENGTH, CONTAINER_LISTING_LIMIT, ACCOUNT_LISTING_LIMIT, \
-    MAX_ACCOUNT_NAME_LENGTH, MAX_CONTAINER_NAME_LENGTH
+from swift.common.constraints import default_constraints, \
+    constraints_conf_exists
 
-default_constraints = dict((
-    ('max_file_size', MAX_FILE_SIZE),
-    ('max_meta_name_length', MAX_META_NAME_LENGTH),
-    ('max_meta_value_length', MAX_META_VALUE_LENGTH),
-    ('max_meta_count', MAX_META_COUNT),
-    ('max_meta_overall_size', MAX_META_OVERALL_SIZE),
-    ('max_object_name_length', MAX_OBJECT_NAME_LENGTH),
-    ('container_listing_limit', CONTAINER_LISTING_LIMIT),
-    ('account_listing_limit', ACCOUNT_LISTING_LIMIT),
-    ('max_account_name_length', MAX_ACCOUNT_NAME_LENGTH),
-    ('max_container_name_length', MAX_CONTAINER_NAME_LENGTH)))
-constraints_conf = ConfigParser()
-conf_exists = constraints_conf.read('/etc/swift/swift.conf')
-# Constraints are set first from the test config, then from
-# /etc/swift/swift.conf if it exists. If swift.conf doesn't exist,
-# then limit test coverage. This allows SAIO tests to work fine but
-# requires remote functional testing to know something about the cluster
-# that is being tested.
 config = get_config('func_test')
 for k in default_constraints:
     if k in config:
         # prefer what's in test.conf
         config[k] = int(config[k])
-    elif conf_exists:
+    elif constraints_conf_exists:
         # swift.conf exists, so use what's defined there (or swift defaults)
         # This normally happens when the test is running locally to the cluster
         # as in a SAIO.
diff --git a/test/sample.conf b/test/sample.conf
index 32d984e0de..161a588aa2 100644
--- a/test/sample.conf
+++ b/test/sample.conf
@@ -25,15 +25,17 @@ password2 = testing2
 username3 = tester3
 password3 = testing3
 
-# Default constraints if not defined here, the test runner will try
-# to set them from /etc/swift/swift.conf. If that file isn't found,
-# the test runner will skip tests that depend on these values.
+# If not defined here, the test runner will try to use the default constraint
+# values as constructed by the constraints module, which will attempt to get
+# them from /etc/swift/swift.conf, if possible. Then, if the swift.conf file
+# isn't found, the test runner will skip tests that depend on those values.
 # Note that the cluster must have "sane" values for the test suite to pass.
 #max_file_size = 5368709122
 #max_meta_name_length = 128
 #max_meta_value_length = 256
 #max_meta_count = 90
 #max_meta_overall_size = 4096
+#max_header_size = 8192
 #max_object_name_length = 1024
 #container_listing_limit = 10000
 #account_listing_limit = 10000