diff --git a/lib/euler/algebra.ex b/lib/euler/algebra.ex
index e871898..cbe4aba 100644
--- a/lib/euler/algebra.ex
+++ b/lib/euler/algebra.ex
@@ -13,6 +13,8 @@ defmodule Euler.Algebra do
   @doc """
   Computes n!
   """
+  def fact(0), do: 1
+  def fact(1), do: 1
   def fact(n), do: fact(n - 1, n)
 
   defp digit_sum(0, acc), do: acc