diff --git a/lib/koans/09_map_sets.ex b/lib/koans/09_map_sets.ex
index 3ac5af1..e851900 100644
--- a/lib/koans/09_map_sets.ex
+++ b/lib/koans/09_map_sets.ex
@@ -9,10 +9,6 @@ defmodule MapSets do
     assert Enum.fetch(@set, 0) == {:ok, ___}
   end
 
-  koan "How large is my map set?" do
-    assert MapSet.size(@set) == ___
-  end
-
   koan "However, I do not allow duplication" do
     new_set = MapSet.new([1, 1, 2, 3, 3, 3])
 
diff --git a/test/koans/map_sets_koans_test.exs b/test/koans/map_sets_koans_test.exs
index a4c5af2..886fb41 100644
--- a/test/koans/map_sets_koans_test.exs
+++ b/test/koans/map_sets_koans_test.exs
@@ -5,7 +5,6 @@ defmodule MapSetsTest do
   test "MapSets" do
     answers = [
       1,
-      5,
       3,
       {:multiple, [false, true]},
       true,