diff --git a/db/migrate/20160720212620_create_signature_tables.rb b/db/migrate/20160720212620_create_signature_tables.rb
index 8c8157d48..f9e2d6c05 100644
--- a/db/migrate/20160720212620_create_signature_tables.rb
+++ b/db/migrate/20160720212620_create_signature_tables.rb
@@ -70,7 +70,7 @@ class CreateSignatureTables < ActiveRecord::Migration
             "SELECT relayable.id, #{order_id}, relayable.author_signature FROM #{relayable_type}s AS relayable " \
             "INNER JOIN people AS author ON relayable.author_id = author.id " \
             "#{parent_join} INNER JOIN people AS parent_author ON parent.author_id = parent_author.id " \
-            "WHERE author.owner_id IS NULL AND parent_author.owner_id IS NOT NULL"
+            "WHERE author.owner_id IS NULL AND parent_author.owner_id IS NOT NULL AND relayable.author_signature IS NOT NULL"
   end
 
   def restore_signatures(relayable_type)