diff --git a/box.py b/box.py
index e66e189..be81ce5 100644
--- a/box.py
+++ b/box.py
@@ -100,7 +100,9 @@ class BoundingBox (object):
         return itertools.product(xrange(self.mincx,self.maxcx), xrange(self.mincz, self.maxcz));
         
     
-    
+    @property
+    def isChunkAligned(self):
+        return (self.origin[0] & 0xf == 0) and (self.origin[2] & 0xf == 0)
     
     def __contains__(self, pos):
         x,y,z = pos;
diff --git a/mclevel.py b/mclevel.py
index 3e611b9..b234c25 100644
--- a/mclevel.py
+++ b/mclevel.py
@@ -1024,8 +1024,7 @@ class MCLevel(object):
         
         destBox = BoundingBox(destPoint, sourceBox.size);
         
-        if ((sourceBox.origin[0] & 0xf == 0) and 
-            (sourceBox.origin[2] & 0xf == 0)):
+        if (sourceBox.isChunkAligned):
             #create chunks in the destination area corresponding only to chunks
             #present in the source
             chunks = sourceBox.chunkPositions