diff --git a/chunk.py b/chunk.py
index 47d1dc8..fef3a84 100644
--- a/chunk.py
+++ b/chunk.py
@@ -15,7 +15,6 @@
 
 import numpy
 from PIL import Image, ImageDraw
-from itertools import izip, count
 import os.path
 import hashlib
 
diff --git a/quadtree.py b/quadtree.py
index 9fb8128..553c67f 100644
--- a/quadtree.py
+++ b/quadtree.py
@@ -173,8 +173,8 @@ class QuadtreeGen(object):
             newdir = "new" + str(dirnum)
             newdirpath = getpath(newdir)
 
-            files = [str(dirnum)+"."+imgformat, str(dirnum)+".hash", str(dirnum)]
-            newfiles = [str(newnum)+"."+imgformat, str(newnum)+".hash", str(newnum)]
+            files = [str(dirnum)+"."+self.imgformat, str(dirnum)+".hash", str(dirnum)]
+            newfiles = [str(newnum)+"."+self.imgformat, str(newnum)+".hash", str(newnum)]
 
             os.mkdir(newdirpath)
             for f, newf in zip(files, newfiles):
diff --git a/world.py b/world.py
index cc3f545..231287b 100644
--- a/world.py
+++ b/world.py
@@ -21,7 +21,6 @@ import sys
 import logging
 
 import numpy
-from PIL import Image
 
 import chunk
 import nbt