diff --git a/conservancy_beancount/_typing.py b/conservancy_beancount/beancount_types.py
similarity index 80%
rename from conservancy_beancount/_typing.py
rename to conservancy_beancount/beancount_types.py
index 6bae7cc..e89197b 100644
--- a/conservancy_beancount/_typing.py
+++ b/conservancy_beancount/beancount_types.py
@@ -1,4 +1,4 @@
-"""Type definitions for Conservancy Beancount code"""
+"""Type definitions for Beancount data structures"""
 # Copyright © 2020  Brett Smith
 #
 # This program is free software: you can redistribute it and/or modify
@@ -18,7 +18,6 @@ import abc
 import datetime
 
 import beancount.core.data as bc_data
-from .plugin import errors
 
 from typing import (
     Any,
@@ -33,21 +32,11 @@ from typing import (
 )
 
 Account = bc_data.Account
-Error = errors._BaseError
-ErrorIter = Iterable[Error]
 MetaKey = str
 MetaValue = Any
 MetaValueEnum = str
 Posting = bc_data.Posting
 
-class LessComparable(metaclass=abc.ABCMeta):
-    @abc.abstractmethod
-    def __le__(self, other: Any) -> bool: ...
-
-    @abc.abstractmethod
-    def __lt__(self, other: Any) -> bool: ...
-
-
 class Directive(NamedTuple):
     meta: bc_data.Meta
     date: datetime.date
diff --git a/conservancy_beancount/plugin/errors.py b/conservancy_beancount/errors.py
similarity index 92%
rename from conservancy_beancount/plugin/errors.py
rename to conservancy_beancount/errors.py
index 6bd6842..e1eb348 100644
--- a/conservancy_beancount/plugin/errors.py
+++ b/conservancy_beancount/errors.py
@@ -14,7 +14,11 @@
 # 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/>.
 
-class _BaseError(Exception):
+from typing import (
+    Iterable,
+)
+
+class Error(Exception):
     def __init__(self, message, entry, source=None):
         self.message = message
         self.entry = entry
@@ -28,7 +32,9 @@ class _BaseError(Exception):
         )
 
 
-class InvalidMetadataError(_BaseError):
+Iter = Iterable[Error]
+
+class InvalidMetadataError(Error):
     def __init__(self, txn, post, key, value=None, source=None):
         if value is None:
             msg_fmt = "{post.account} missing {key}"
diff --git a/conservancy_beancount/plugin/__init__.py b/conservancy_beancount/plugin/__init__.py
index b4370f9..797bf57 100644
--- a/conservancy_beancount/plugin/__init__.py
+++ b/conservancy_beancount/plugin/__init__.py
@@ -28,15 +28,17 @@ from typing import (
     Tuple,
     Type,
 )
-from .._typing import (
+from ..beancount_types import (
     ALL_DIRECTIVES,
     Directive,
-    Error,
 )
 from .core import (
     Hook,
     HookName,
 )
+from ..errors import (
+    Error,
+)
 
 __plugins__ = ['run']
 
diff --git a/conservancy_beancount/plugin/core.py b/conservancy_beancount/plugin/core.py
index 41b8dff..0f3c3f9 100644
--- a/conservancy_beancount/plugin/core.py
+++ b/conservancy_beancount/plugin/core.py
@@ -18,9 +18,10 @@ import abc
 import datetime
 import re
 
-from . import errors as errormod
+from .. import errors as errormod
 
 from typing import (
+    Any,
     FrozenSet,
     Generic,
     Iterable,
@@ -29,12 +30,9 @@ from typing import (
     Optional,
     TypeVar,
 )
-from .._typing import (
+from ..beancount_types import (
     Account,
     Directive,
-    Error,
-    ErrorIter,
-    LessComparable,
     MetaKey,
     MetaValue,
     MetaValueEnum,
@@ -62,7 +60,7 @@ class Hook(Generic[Entry], metaclass=abc.ABCMeta):
     HOOK_GROUPS: FrozenSet[HookName] = frozenset()
 
     @abc.abstractmethod
-    def run(self, entry: Entry) -> ErrorIter: ...
+    def run(self, entry: Entry) -> errormod.Iter: ...
 
     def __init_subclass__(cls):
         cls.DIRECTIVE = cls.__orig_bases__[0].__args__[0]
@@ -72,6 +70,14 @@ TransactionHook = Hook[Transaction]
 
 ### HELPER CLASSES
 
+class LessComparable(metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def __le__(self, other: Any) -> bool: ...
+
+    @abc.abstractmethod
+    def __lt__(self, other: Any) -> bool: ...
+
+
 CT = TypeVar('CT', bound=LessComparable)
 class _GenericRange(Generic[CT]):
     """Convenience class to check whether a value is within a range.
@@ -200,14 +206,14 @@ class _PostingHook(TransactionHook, metaclass=abc.ABCMeta):
     def _run_on_post(self, txn: Transaction, post: Posting) -> bool:
         return True
 
-    def run(self, txn: Transaction) -> ErrorIter:
+    def run(self, txn: Transaction) -> errormod.Iter:
         if self._run_on_txn(txn):
             for index, post in enumerate(txn.postings):
                 if self._run_on_post(txn, post):
                     yield from self.post_run(txn, post, index)
 
     @abc.abstractmethod
-    def post_run(self, txn: Transaction, post: Posting, post_index: int) -> ErrorIter: ...
+    def post_run(self, txn: Transaction, post: Posting, post_index: int) -> errormod.Iter: ...
 
 
 class _NormalizePostingMetadataHook(_PostingHook):
@@ -229,14 +235,14 @@ class _NormalizePostingMetadataHook(_PostingHook):
     def _default_value(self, txn: Transaction, post: Posting) -> MetaValueEnum:
         raise errormod.InvalidMetadataError(txn, post, self.METADATA_KEY)
 
-    def post_run(self, txn: Transaction, post: Posting, post_index: int) -> ErrorIter:
+    def post_run(self, txn: Transaction, post: Posting, post_index: int) -> errormod.Iter:
         source_value = self._meta_get(txn, post, self.METADATA_KEY)
         set_value = source_value
-        error: Optional[Error] = None
+        error: Optional[errormod.Error] = None
         if source_value is None:
             try:
                 set_value = self._default_value(txn, post)
-            except errormod._BaseError as error_:
+            except errormod.Error as error_:
                 error = error_
         else:
             try:
diff --git a/conservancy_beancount/plugin/meta_expense_allocation.py b/conservancy_beancount/plugin/meta_expense_allocation.py
index 74ede4d..0a08823 100644
--- a/conservancy_beancount/plugin/meta_expense_allocation.py
+++ b/conservancy_beancount/plugin/meta_expense_allocation.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 from . import core
-from .._typing import (
+from ..beancount_types import (
     MetaValueEnum,
     Posting,
     Transaction,
diff --git a/conservancy_beancount/plugin/meta_tax_implication.py b/conservancy_beancount/plugin/meta_tax_implication.py
index 044eeca..a9121f3 100644
--- a/conservancy_beancount/plugin/meta_tax_implication.py
+++ b/conservancy_beancount/plugin/meta_tax_implication.py
@@ -17,7 +17,7 @@
 import decimal
 
 from . import core
-from .._typing import (
+from ..beancount_types import (
     Posting,
     Transaction,
 )
diff --git a/tests/test_plugin_run.py b/tests/test_plugin_run.py
index f5f910d..9c9d229 100644
--- a/tests/test_plugin_run.py
+++ b/tests/test_plugin_run.py
@@ -18,14 +18,14 @@ import pytest
 
 from . import testutil
 
-from conservancy_beancount import plugin, _typing
+from conservancy_beancount import beancount_types, plugin
 
 CONFIG_MAP = {}
 HOOK_REGISTRY = plugin.HookRegistry()
 
 @HOOK_REGISTRY.add_hook
 class TransactionCounter:
-    DIRECTIVE = _typing.Transaction
+    DIRECTIVE = beancount_types.Transaction
     HOOK_GROUPS = frozenset()
 
     def run(self, txn):
@@ -34,7 +34,7 @@ class TransactionCounter:
 
 @HOOK_REGISTRY.add_hook
 class PostingCounter(TransactionCounter):
-    DIRECTIVE = _typing.Transaction
+    DIRECTIVE = beancount_types.Transaction
     HOOK_GROUPS = frozenset(['posting'])
 
     def run(self, txn):