diff --git a/PIL/SpiderImagePlugin.py b/PIL/SpiderImagePlugin.py
index cd97c524d..ec8267f22 100644
--- a/PIL/SpiderImagePlugin.py
+++ b/PIL/SpiderImagePlugin.py
@@ -74,11 +74,9 @@ def isSpiderImage(filename):
     fp = open(filename,'rb')
     f = fp.read(92)   # read 23 * 4 bytes
     fp.close()
-    bigendian = 1
     t = struct.unpack('>23f',f)    # try big-endian first
     hdrlen = isSpiderHeader(t)
     if hdrlen == 0:
-        bigendian = 0
         t = struct.unpack('<23f',f)  # little-endian
         hdrlen = isSpiderHeader(t)
     return hdrlen