diff --git a/Lib/distutils/mwerkscompiler.py b/Lib/distutils/mwerkscompiler.py
index 2edc8259bfd..981fd95f01d 100644
--- a/Lib/distutils/mwerkscompiler.py
+++ b/Lib/distutils/mwerkscompiler.py
@@ -114,6 +114,8 @@ def link (self,
         # into the project.
         if output_filename[-8:] == '.ppc.slb':
             basename = output_filename[:-8]
+        elif output_filename[-11:] == '.carbon.slb':
+            basename = output_filename[:-11]
         else:
             basename = os.path.strip(output_filename)[0]
         projectname = basename + '.mcp'
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 91f9279d875..473faea85e8 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -339,7 +339,11 @@ def _init_mac():
     # XXX hmmm.. a normal install puts include files here
     g['INCLUDEPY'] = get_python_inc(plat_specific=0)
 
+    import MacOS
+    if not hasattr(MacOS, 'runtimemodel'):
     g['SO'] = '.ppc.slb'
+    else:
+        g['SO'] = '.%s.slb' % MacOS.runtimemodel
 
     # XXX are these used anywhere?
     g['install_lib'] = os.path.join(EXEC_PREFIX, "Lib")