diff --git a/doc/changelog.rst b/doc/changelog.rst
index 01ca9a9..23a48c7 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -7,6 +7,8 @@ py2app 0.28
 * Fix hard crash in "rtree" recipe when the package contents doesn't
   match the recipe expectations.
 
+* #408: Add definition of ``site.PREFIXES``
+
 * #412: Fix incompatibility with setuptools 60.8.1 
 
   The setuptools recipe did not recoginize all vendored dependencies 
diff --git a/py2app/apptemplate/lib/site.py b/py2app/apptemplate/lib/site.py
index d867838..7999a25 100644
--- a/py2app/apptemplate/lib/site.py
+++ b/py2app/apptemplate/lib/site.py
@@ -203,3 +203,6 @@ def getusersitepackages():
 builtins.help = _sitebuiltins._Helper()
 builtins.quit = _sitebuiltins.Quitter('quit', 'Ctrl-D (i.e. EOF)')
 builtins.exit = _sitebuiltins.Quitter('exit', 'Ctrl-D (i.e. EOF)')
+
+# Prefixes for site-packages; add additional prefixes like /usr/local here
+PREFIXES = [sys.prefix, sys.exec_prefix]