diff --git a/lib/language/program.rb b/lib/language/program.rb
index 42b89f4..1e3eb54 100644
--- a/lib/language/program.rb
+++ b/lib/language/program.rb
@@ -10,8 +10,9 @@ module Rpn
         # we trim enclosing «»
         parsed_input = Rpn::Parser.new.parse_input( args[0][:value][1..-2] )
 
-        stack, dictionary = Rpn::Runner.new.run_input( stack, dictionary, parsed_input )
+        stack, _dictionary = Rpn::Runner.new.run_input( stack, dictionary, parsed_input )
         # TODO: check that STO actually updates dictionary
+
         stack
       end
     end
diff --git a/spec/language_program_spec.rb b/spec/language_program_spec.rb
index bbb9255..51b548d 100644
--- a/spec/language_program_spec.rb
+++ b/spec/language_program_spec.rb
@@ -10,8 +10,10 @@ require_relative '../lib/runner'
 
 class TestParser < Test::Unit::TestCase
   def test_eval
-    stack, _dico = Rpn::Core::Program.eval( [{ value: '« 2 dup * »', type: :program }], Rpn::Dictionary.new )
-    assert_equal [{ value: 4, type: :numeric }],
+    stack = Rpn::Core::Program.eval( [{ value: '« 2 dup * dup »', type: :program }], Rpn::Dictionary.new )
+
+    assert_equal [{ value: 4, type: :numeric },
+                  { value: 4, type: :numeric }],
                  stack
   end
 end