diff -r ab162f925761 Lib/ctypes/test/test_structures.py
--- a/Lib/ctypes/test/test_structures.py	Mon Jul 11 01:39:35 2011 +0200
+++ b/Lib/ctypes/test/test_structures.py	Mon Jul 11 18:30:29 2011 -0700
@@ -439,5 +439,34 @@
         else:
             self.fail("AttributeError not raised")
 
+# ensure _other_endian function from _endian.py works on Structure types
+# check both BigEndianStructure and LittleEndianStructure to make sure
+# we hit _other_endian regardless of machine endianness 
+class TestNestedStructures(unittest.TestCase):
+    # helper function declares nested structures with given endianness
+    def define_structures(self, endianness):
+        class NestedStructure(endianness):
+            _fields_ = [("spam", c_long),
+                        ("eggs", c_long)]
+
+        class TestStructure(endianness):
+            _fields_ = [("menu", NestedStructure)]
+
+    # test defining little endian nested structures
+    def test_little_endian_nested(self):
+        try:
+            self.define_structures(LittleEndianStructure)
+        except:
+            # no exception should be thrown
+            self.fail("Defining nested LittleEndianStructure failed")
+
+    # test defining big endian nested structure
+    def test_big_endian_nested(self):
+        try:
+            self.define_structures(BigEndianStructure)
+        except:
+            # no exception should be thrown
+            self.fail("Defining nested BigEndianStructure failed")
+
 if __name__ == '__main__':
     unittest.main()