diff --git a/modules/field/modules/list/list.module b/modules/field/modules/list/list.module
index 1d72be4..73a8e60 100644
--- a/modules/field/modules/list/list.module
+++ b/modules/field/modules/list/list.module
@@ -345,7 +345,8 @@ function list_field_update_forbid($field, $prior_field, $has_data) {
     // Forbid any update that removes allowed values with actual data.
     $lost_keys = array_diff(array_keys($prior_field['settings']['allowed_values']), array_keys($field['settings']['allowed_values']));
     if (_list_values_in_use($field, $lost_keys)) {
-      throw new FieldUpdateForbiddenException(t('Cannot update a list field to not include keys with existing data.'));
+      throw new FieldUpdateForbiddenException(t('A list field (@field_name) with existing data cannot have its keys changed.',
+                                                array('@field_name' => $field['field_name'])));
     }
   }
 }