diff --git a/hs/src/Aoc/Y2020/D17.hs b/hs/src/Aoc/Y2020/D17.hs
index 390eccb..eb4cc72 100644
--- a/hs/src/Aoc/Y2020/D17.hs
+++ b/hs/src/Aoc/Y2020/D17.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE Strict            #-}
 
 module Aoc.Y2020.D17
   ( day