diff --git a/tailbone/views/batch/core.py b/tailbone/views/batch/core.py
index 1d539dd2..b872e736 100644
--- a/tailbone/views/batch/core.py
+++ b/tailbone/views/batch/core.py
@@ -603,8 +603,8 @@ class BatchMasterView(MasterView):
     # TODO
     execution_options_schema = None
 
-    def make_execute_schema(self):
-        return self.execution_options_schema()
+    def make_execute_schema(self, batch):
+        return self.execution_options_schema().bind(batch=batch)
 
     def make_execute_form(self, batch=None, **kwargs):
         """
@@ -616,11 +616,15 @@ class BatchMasterView(MasterView):
         if self.has_execution_options(batch):
             if batch is None:
                 batch = self.model_class
-            schema = self.make_execute_schema()
+            schema = self.make_execute_schema(batch)
             for field in schema:
-                key = 'batch.{}.execute_option.{}'.format(batch.batch_key, field.name)
-                if key in self.request.session:
-                    defaults[field.name] = self.request.session[key]
+
+                # if field does not yet have a default, maybe provide one from session storage
+                if field.default is colander.null:
+                    key = 'batch.{}.execute_option.{}'.format(batch.batch_key, field.name)
+                    if key in self.request.session:
+                        defaults[field.name] = self.request.session[key]
+
         else:
             schema = colander.Schema()