diff --git a/lib/core/store.rb b/lib/core/store.rb
index 20f06de..9c592c7 100644
--- a/lib/core/store.rb
+++ b/lib/core/store.rb
@@ -27,7 +27,7 @@ module Rpl
       def rcl( stack, dictionary )
         stack, args = Rpl::Lang::Core.stack_extract( stack, [%i[name]] )
 
-        word = dictionary[ args[0][:value][1..-2] ]
+        word = dictionary.lookup( args[0][:value][1..-2] )
 
         stack, dictionary = word.call( stack, dictionary, true ) unless word.nil?
 
diff --git a/lib/dictionary.rb b/lib/dictionary.rb
index 528f594..7e4e37e 100644
--- a/lib/dictionary.rb
+++ b/lib/dictionary.rb
@@ -213,7 +213,7 @@ module Rpl
         @vars = {}
       end
 
-      def []( name )
+      def lookup( name )
         word = @words[ name ]
         word ||= @vars[ name ]
 
diff --git a/lib/runner.rb b/lib/runner.rb
index 7f064e8..d020b84 100644
--- a/lib/runner.rb
+++ b/lib/runner.rb
@@ -9,7 +9,7 @@ module Rpl
         input.each do |elt|
           case elt[:type]
           when :word
-            command = dictionary[ elt[:value] ]
+            command = dictionary.lookup( elt[:value] )
 
             if command.nil?
               stack << { type: :name, value: "'#{elt[:value]}'" }
diff --git a/spec/language_store_spec.rb b/spec/language_store_spec.rb
index f672e55..f2026ca 100644
--- a/spec/language_store_spec.rb
+++ b/spec/language_store_spec.rb
@@ -25,7 +25,7 @@ class TestLanguageProgram < Test::Unit::TestCase
   def test_purge
     lang = Rpl::Language.new
     lang.run '« 2 dup * » \'quatre\' sto \'quatre\' purge'
-    assert_nil lang.dictionary['quatre']
+    assert_nil lang.dictionary.lookup( 'quatre' )
   end
 
   def test_vars