diff --git a/src/com/annimon/everlastingsummer/Lexer.java b/src/com/annimon/everlastingsummer/Lexer.java
index 65b59e1..adbaff7 100644
--- a/src/com/annimon/everlastingsummer/Lexer.java
+++ b/src/com/annimon/everlastingsummer/Lexer.java
@@ -1,7 +1,10 @@
 package com.annimon.everlastingsummer;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
+import java.util.Map;
 
 /**
  * @author aNNiMON
@@ -22,37 +25,42 @@ public final class Lexer {
         TokenType.LPAREN, TokenType.RPAREN, TokenType.LBRACKET, TokenType.RBRACKET,
         TokenType.COMMAND, TokenType.COLON,
     };
-    
-    private static final String[] KEYWORDS = {
-        "play", "stop",
-        "music", "ambience", "sound", "sound_loop",
-        "fadein", "fadeout",
+
+    private static final Map<String, TokenType> KEYWORDS;
+    static {
+        KEYWORDS = new HashMap<String, TokenType>();
+        KEYWORDS.put("play", TokenType.PLAY);
+        KEYWORDS.put("stop", TokenType.STOP);
+        KEYWORDS.put("music", TokenType.MUSIC);
+        KEYWORDS.put("ambience", TokenType.AMBIENCE);
+        KEYWORDS.put("sound", TokenType.SOUND);
+        KEYWORDS.put("sound_loop", TokenType.SOUNDLOOP);
+        KEYWORDS.put("fadein", TokenType.FADEIN);
+        KEYWORDS.put("fadeout", TokenType.FADEOUT);
         
-        "scene", "anim", "bg", "cg",
-        "at",
-        "window", "hide", "show",
-        "with",
+        KEYWORDS.put("scene", TokenType.SCENE);
+        KEYWORDS.put("anim", TokenType.ANIM);
+        KEYWORDS.put("bg", TokenType.BG);
+        KEYWORDS.put("cg", TokenType.CG);
+        KEYWORDS.put("at", TokenType.AT);
+        KEYWORDS.put("window", TokenType.WINDOW);
+        KEYWORDS.put("hide", TokenType.HIDE);
+        KEYWORDS.put("show", TokenType.SHOW);
+        KEYWORDS.put("with", TokenType.WITH);
         
-        "return", "menu", "endmenu", "jump", "label",
+        KEYWORDS.put("return", TokenType.RETURN);
+        KEYWORDS.put("menu", TokenType.MENU);
+        KEYWORDS.put("endmenu", TokenType.ENDMENU);
+        KEYWORDS.put("jump", TokenType.JUMP);
+        KEYWORDS.put("label", TokenType.LABEL);
         
-        "renpy.pause", "persistent.sprite_time",
-        "prolog_time", "day_time", "sunset_time", "night_time"
-    };
-    private static final TokenType[] KEYWORD_TYPES = new TokenType[] {
-        TokenType.PLAY, TokenType.STOP,
-        TokenType.MUSIC, TokenType.AMBIENCE, TokenType.SOUND, TokenType.SOUNDLOOP,
-        TokenType.FADEIN, TokenType.FADEOUT,
-        
-        TokenType.SCENE, TokenType.ANIM, TokenType.BG, TokenType.CG,
-        TokenType.AT,
-        TokenType.WINDOW, TokenType.HIDE, TokenType.SHOW,
-        TokenType.WITH,
-        
-        TokenType.RETURN, TokenType.MENU, TokenType.ENDMENU, TokenType.JUMP, TokenType.LABEL, 
-        
-        TokenType.RENPY_PAUSE, TokenType.PERSISTENT_SPRITE_TIME,
-        TokenType.PROLOG_TIME, TokenType.DAY_TIME, TokenType.SUNSET_TIME, TokenType.NIGHT_TIME
-    };
+        KEYWORDS.put("renpy.pause", TokenType.RENPY_PAUSE);
+        KEYWORDS.put("persistent.sprite_time", TokenType.PERSISTENT_SPRITE_TIME);
+        KEYWORDS.put("prolog_time", TokenType.PROLOG_TIME);
+        KEYWORDS.put("day_time", TokenType.DAY_TIME);
+        KEYWORDS.put("sunset_time", TokenType.SUNSET_TIME);
+        KEYWORDS.put("night_time", TokenType.NIGHT_TIME);
+    }
     
     private TokenizeState state;
     private int pos;
@@ -117,14 +125,8 @@ public final class Lexer {
         if (Character.isLetterOrDigit(ch) || (ch == '_') || (ch == '.')) {
             buffer.append(ch);
         } else {
-            final String word = buffer.toString();
-            for (int i = 0; i < KEYWORDS.length; i++) {
-                if (KEYWORDS[i].equalsIgnoreCase(word)) {
-                    addToken(KEYWORD_TYPES[i]);
-                    return;
-                }
-            }
-            addToken(TokenType.WORD);
+            final String word = buffer.toString().toLowerCase(Locale.ENGLISH);
+            addToken(KEYWORDS.containsKey(word) ? KEYWORDS.get(word) : TokenType.WORD);
         }
     }