diff --git a/docs/ALGORITHM.md b/docs/ALGORITHM.md
index 4f4f61c..8c598be 100644
--- a/docs/ALGORITHM.md
+++ b/docs/ALGORITHM.md
@@ -187,7 +187,7 @@ zs :: [Int]
 zs = 0 : concatMap (\i -> [i, -i]) [1..]
 
 gaussianInts :: [Complex Int]
-gaussianInts = map snd (applyMerge (\x y -> (x*x + y*y, x :+ y)) ints ints)
+gaussianInts = map snd (applyMerge (\x y -> (x*x + y*y, x :+ y)) zs zs)
 ```
 
 Square-free integers ([Wikipedia](https://en.wikipedia.org/wiki/Square-free_integer)):