diff --git a/lib/koans/13_functions.ex b/lib/koans/13_functions.ex
index c20a4785..18a0c66b 100644
--- a/lib/koans/13_functions.ex
+++ b/lib/koans/13_functions.ex
@@ -78,6 +78,16 @@ defmodule Functions do
     assert three_times.("foo") == ___
   end
 
+  koan "You can use pattern matching to define multiple cases for anonymous functions" do
+    format_result = fn
+      {:ok, result} -> "Success is #{result}"
+      {:error, reason} -> "You just lost #{reason}"
+    end
+
+    assert format_result.({:ok, "no accident"}) == ___
+    assert format_result.({:error, "the game"}) == ___
+  end
+
   def times_five_and_then(number, fun), do: fun.(number * 5)
   def square(number), do: number * number