diff --git a/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py b/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
index ae378fc..090e16d 100644
--- a/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
+++ b/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
@@ -24,6 +24,7 @@
 CORE-POS -> Catapult Inventory Workbook
 """
 
+import datetime
 import logging
 
 from sqlalchemy.exc import ProgrammingError
@@ -117,6 +118,9 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
     def setup(self):
         super(InventoryItemImporter, self).setup()
 
+        # this is used for sorting, when a value has no date
+        self.old_date = datetime.date(1900, 1, 1)
+
         self.ignored_upcs = self.config.getlist(
             'corepos', 'exporting.catapult_inventory.ignored_upcs')
 
@@ -341,7 +345,7 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
                            product.upc, len(vendor_items), product)
 
                     # sort the list so most recently modified is first
-                    vendor_items.sort(key=lambda item: item.modified,
+                    vendor_items.sort(key=lambda item: item.modified or self.old_date,
                                       reverse=True)
 
             # use the "first" vendor item available