diff --git a/chunk.py b/chunk.py
index f6042bf..181553e 100644
--- a/chunk.py
+++ b/chunk.py
@@ -131,8 +131,12 @@ def find_oldimage(chunkfile, cached, cave):
     return oldimg, oldimg_path
 
 def check_cache(chunkfile, oldimg):
-    if os.path.getmtime(chunkfile) <= os.path.getmtime(oldimg[1]):
-        return self.oldimg_path
+    try:
+        if oldimg[1] and os.path.getmtime(chunkfile) <= os.path.getmtime(oldimg[1]):
+            return True
+        return False
+    except OSError:
+        return False
 
 def render_and_save(chunkfile, cachedir, worldobj, oldimg, cave=False, queue=None):
     """Used as the entry point for the multiprocessing workers (since processes
diff --git a/world.py b/world.py
index be90a73..effc46a 100644
--- a/world.py
+++ b/world.py
@@ -301,7 +301,7 @@ class WorldRenderer(object):
                         continue
 
                 oldimg = chunk.find_oldimage(chunkfile, cached, self.caves)
-                if oldimg[1] and (os.path.getmtime(chunkfile) <= os.path.getmtime(oldimg[1])):
+                if chunk.check_cache(chunkfile, oldimg[1]):
                     result = oldimg[1]
                 else:
                     result = chunk.render_and_save(chunkfile, self.cachedir, self, oldimg, queue=q)
@@ -331,7 +331,7 @@ class WorldRenderer(object):
                         continue
 
                 oldimg = chunk.find_oldimage(chunkfile, cached, self.caves)
-                if oldimg[1] and (os.path.getmtime(chunkfile) <= os.path.getmtime(oldimg[1])):
+                if chunk.check_cache(chunkfile, oldimg[1]):
                     result = FakeAsyncResult(oldimg[1])
                 else:
                     result = pool.apply_async(chunk.render_and_save,