diff --git a/rattail_corepos/importing/corepos/db.py b/rattail_corepos/importing/corepos/db.py
index b9d7a3b..7957e8d 100644
--- a/rattail_corepos/importing/corepos/db.py
+++ b/rattail_corepos/importing/corepos/db.py
@@ -285,6 +285,17 @@ class MemberEquityPaymentImporter(FromCOREPOS, corepos_importing.model.MemberEqu
                                                        query=query,
                                                        key=key)
 
+    def cache_query(self):
+        query = super().cache_query()
+        model = self.model
+
+        # ignore existing payments not known to be in CORE
+        # TODO: is this in fact a good idea?
+        query = query.join(model.CoreMemberEquityPayment)\
+                     .filter(model.CoreMemberEquityPayment.corepos_transaction_number != None)
+
+        return query
+
     def get_member(self, card_number):
         if hasattr(self, 'members_by_card_number'):
             return self.members_by_card_number.get(card_number)