Use __builtin__ instead of builtin
diff --git a/Lib/sunau.py b/Lib/sunau.py
index 17fa60d..631d9e8 100644
--- a/Lib/sunau.py
+++ b/Lib/sunau.py
@@ -153,8 +153,8 @@
 
 	def __init__(self, f):
 		if type(f) == type(''):
-			import builtin
-			f = builtin.open(f, 'r')
+			import __builtin__
+			f = __builtin__.open(f, 'r')
 		self.initfp(f)
 
 	def __del__(self):
@@ -284,8 +284,8 @@
 
 	def __init__(self, f):
 		if type(f) == type(''):
-			import builtin
-			f = builtin.open(f, 'w')
+			import __builtin__
+			f = __builtin__.open(f, 'w')
 		self.initfp(f)
 
 	def __del__(self):