diff --git a/conservancy_beancount/plugin/core.py b/conservancy_beancount/plugin/core.py
index befa40c..d3cb6a8 100644
--- a/conservancy_beancount/plugin/core.py
+++ b/conservancy_beancount/plugin/core.py
@@ -36,6 +36,36 @@ class _GenericRange:
         return self.start <= item < self.stop
 
 
+class MetadataEnum:
+    def __init__(self, key, standard_values, aliases_map):
+        self.key = key
+        self._stdvalues = frozenset(standard_values)
+        self._aliases = dict(aliases_map)
+        self._aliases.update((v, v) for v in standard_values)
+        assert self._stdvalues == set(self._aliases.values())
+
+    def __repr__(self):
+        return "{}<{}>".format(type(self).__name__, self.key)
+
+    def __contains__(self, key):
+        return key in self._aliases
+
+    def __getitem__(self, key):
+        return self._aliases[key]
+
+    def __iter__(self):
+        return iter(self._stdvalues)
+
+    def get(self, key, default_key=None):
+        try:
+            return self[key]
+        except KeyError:
+            if default_key is None:
+                return None
+            else:
+                return self[default_key]
+
+
 class PostingChecker:
     ACCOUNTS = ('',)
     TXN_DATE_RANGE = _GenericRange(DEFAULT_START_DATE, DEFAULT_STOP_DATE)
@@ -76,7 +106,7 @@ class PostingChecker:
                 errors.append(error)
         else:
             try:
-                set_value = self.VALUES_ENUM[source_value].value
+                set_value = self.VALUES_ENUM[source_value]
             except KeyError:
                 errors.append(errormod.InvalidMetadataError(
                     txn, post, self.METADATA_KEY, source_value,
diff --git a/conservancy_beancount/plugin/meta_expense_allocation.py b/conservancy_beancount/plugin/meta_expense_allocation.py
index e1e732e..603b2d7 100644
--- a/conservancy_beancount/plugin/meta_expense_allocation.py
+++ b/conservancy_beancount/plugin/meta_expense_allocation.py
@@ -14,27 +14,23 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-import enum
-
 from . import core
 
-class ExpenseAllocations(enum.Enum):
-    administration = 'administration'
-    fundraising = 'fundraising'
-    program = 'program'
-
-    admin = administration
-
-
 class MetaExpenseAllocation(core.PostingChecker):
     ACCOUNTS = ('Expenses:',)
     METADATA_KEY = 'expenseAllocation'
-    VALUES_ENUM = ExpenseAllocations
+    VALUES_ENUM = core.MetadataEnum(METADATA_KEY, {
+        'administration',
+        'fundraising',
+        'program',
+    }, {
+        'admin': 'administration',
+    })
     DEFAULT_VALUES = {
-        'Expenses:Services:Accounting': VALUES_ENUM.administration,
-        'Expenses:Services:Administration': VALUES_ENUM.administration,
-        'Expenses:Services:Fundraising': VALUES_ENUM.fundraising,
+        'Expenses:Services:Accounting': VALUES_ENUM['administration'],
+        'Expenses:Services:Administration': VALUES_ENUM['administration'],
+        'Expenses:Services:Fundraising': VALUES_ENUM['fundraising'],
     }
 
     def _default_value(self, txn, post):
-        return self.DEFAULT_VALUES.get(post.account, self.VALUES_ENUM.program).value
+        return self.DEFAULT_VALUES.get(post.account, 'program')