diff --git a/lib/treat/version.rb b/lib/treat/version.rb
index f374263..2fc9e94 100644
--- a/lib/treat/version.rb
+++ b/lib/treat/version.rb
@@ -1,12 +1,12 @@
 module Treat
-  
+
   # The current version of Treat.
   VERSION = '2.1.0'
-  
+
   # Treat requires Ruby >= 1.9.2
   if RUBY_VERSION < '1.9.2'
     raise "Treat requires Ruby version 1.9.2 " +
     "or higher, but current is #{RUBY_VERSION}."
   end
 
-end
\ No newline at end of file
+end
diff --git a/lib/treat/workers/lexicalizers/sensers/wordnet.rb b/lib/treat/workers/lexicalizers/sensers/wordnet.rb
index 3706e0f..a9c0e3e 100755
--- a/lib/treat/workers/lexicalizers/sensers/wordnet.rb
+++ b/lib/treat/workers/lexicalizers/sensers/wordnet.rb
@@ -20,9 +20,6 @@ class Treat::Workers::Lexicalizers::Sensers::Wordnet
   # Require an adaptor for Wordnet synsets.
   require_relative 'wordnet/synset'
 
-  # Noun, adjective and verb indexes.
-  @@indexes = {}
-
   # Obtain lexical information about a word using the
   # ruby 'wordnet' gem.
   def self.sense(word, options = nil)
@@ -49,9 +46,9 @@ class Treat::Workers::Lexicalizers::Sensers::Wordnet
       return []
     end
 
-    cat = category.to_s.capitalize
+    cat = abbreviate(category)
 
-    lemma = ::WordNet::Lemma.find(word.value.downcase, cat.to_sym)
+    lemma = ::WordNet::Lemma.find(word.value.downcase, cat)
 
     return [] if lemma.nil?
     synsets = []
@@ -69,4 +66,14 @@ class Treat::Workers::Lexicalizers::Sensers::Wordnet
     end
   end
 
+  def self.abbreviate category
+    if category == 'adjective'
+      :adj
+    elsif category == 'adverb'
+      :adv
+    else
+      category.to_sym
+    end
+  end
+
 end