diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index b8e4952fee1..f4bb0633c5f 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -165,11 +165,21 @@ def get_platform():
                     raise ValueError(
                        "Don't know machine value for archs=%r"%(archs,))
 
+            elif machine == 'i386':
+                # On OSX the machine type returned by uname is always the
+                # 32-bit variant, even if the executable architecture is
+                # the 64-bit variant
+                if sys.maxint >= 2**32:
+                    machine = 'x86_64'
 
             elif machine in ('PowerPC', 'Power_Macintosh'):
                 # Pick a sane name for the PPC architecture.
                 machine = 'ppc'
 
+                # See 'i386' case
+                if sys.maxint >= 2**32:
+                    machine = 'ppc64'
+
     return "%s-%s-%s" % (osname, release, machine)