diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index 36ac721..c4a8711 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -144,8 +144,7 @@
                 cflags = get_config_vars().get('CFLAGS')
 
                 archs = re.findall('-arch\s+(\S+)', cflags)
-                archs.sort()
-                archs = tuple(archs)
+                archs = tuple(sorted(set(archs)))
 
                 if len(archs) == 1:
                     machine = archs[0]
diff --git a/Misc/NEWS b/Misc/NEWS
index f6f8044..fdd9a42 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -81,6 +81,8 @@
 Library
 -------
 
+- Issue #9164: Ensure sysconfig handles dupblice archs while building on OSX
+
 - Issue #7646: The fnmatch pattern cache no longer grows without bound.
 
 - Issue #9136: Fix 'dictionary changed size during iteration'