1 files changed, 19 insertions, 2 deletions

diff --git a/src/mailman/rest/validator.py b/src/mailman/rest/validator.py
index 6b708872a..748a63d5c 100644
--- a/src/mailman/rest/validator.py
+++ b/src/mailman/rest/validator.py
@@ -27,9 +27,8 @@ __all__ = [
     ]
 
 
-from mailman.core.errors import (
-    ReadOnlyPATCHRequestError, UnknownPATCHRequestError)
 from mailman.interfaces.address import IEmailValidator
+from mailman.interfaces.errors import MailmanError
 from mailman.interfaces.languages import ILanguageManager
 from zope.component import getUtility
 
@@ -37,6 +36,24 @@ from zope.component import getUtility
 COMMASPACE = ', '
 
 
+class RESTError(MailmanError):
+    """Base class for REST API errors."""
+
+
+class UnknownPATCHRequestError(RESTError):
+    """A PATCH request contained an unknown attribute."""
+
+    def __init__(self, attribute):
+        self.attribute = attribute
+
+
+class ReadOnlyPATCHRequestError(RESTError):
+    """A PATCH request contained a read-only attribute."""
+
+    def __init__(self, attribute):
+        self.attribute = attribute
+
+
 
 class enum_validator:
     """Convert an enum value name into an enum value."""