diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 1da7411589..51ba17c9be 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -290,7 +290,7 @@ module ActiveRecord
     def find_one(id)
       id = id.id if ActiveRecord::Base === id
 
-      column = primary_key.column
+      column = columns_hash[primary_key.name.to_s]
 
       substitute = connection.substitute_for(column, @bind_values)
       relation = where(primary_key.eq(substitute))