diff --git a/spec/art-decomp/fsm_spec.rb b/spec/art-decomp/fsm_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/art-decomp/fsm_spec.rb
+++ b/spec/art-decomp/fsm_spec.rb
@@ -147,6 +147,7 @@ module ArtDecomp describe FSM do
       @mc.input_relevance.should    == [nil, nil, 2, 1, 0]
       @opus.input_relevance.should  == [nil, nil, nil, nil, 2, 3, 4, 0, 1]
       @s8.input_relevance.should    == [3, 2, 1, 0, nil, nil, nil]
+      @tt.input_relevance.should    == [1, 3, 2]
     end
 
     it 'should report whether it’s a truth table or a full-blown FSM' do
make sure FSM#input_relevance also works for truth tables