diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index f42c6a18b94..36c4a68494d 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -9,6 +9,7 @@ import re
 import imp
 import sys
 import string
+import platform
 from distutils.errors import DistutilsPlatformError
 from distutils.dep_util import newer
 from distutils.spawn import spawn
@@ -77,6 +78,7 @@ def get_platform ():
         if release[0] >= "5":           # SunOS 5 == Solaris 2
             osname = "solaris"
             release = "%d.%s" % (int(release[0]) - 3, release[2:])
+            machine += ".%s" % platform.architecture()[0]
         # fall through to standard osname-release-machine representation
     elif osname[:4] == "irix":              # could be "irix64"!
         return "%s-%s" % (osname, release)
diff --git a/Misc/NEWS b/Misc/NEWS
index 78945151f24..85887c358b2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -447,6 +447,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #13803: Under Solaris, distutils doesn't include bitness
+  in the directory name.
+
 - Issue #10278: Add time.wallclock() function, monotonic clock.
 
 - Issue #13809: Fix regression where bz2 module wouldn't work when threads are