diff --git a/Lib/packaging/tests/support.py b/Lib/packaging/tests/support.py
index 06f06c9..d76d3db 100644
--- a/Lib/packaging/tests/support.py
+++ b/Lib/packaging/tests/support.py
@@ -342,7 +342,7 @@
         srcdir = sysconfig.get_config_var('projectbase')
         path = os.path.join(os.getcwd(), srcdir, 'Modules', 'xxmodule.c')
     else:
-        os.path.join(os.path.dirname(__file__), 'xxmodule.c')
+        path = os.path.join(os.path.dirname(__file__), 'xxmodule.c')
     if os.path.exists(path):
         return path
 
diff --git a/Lib/packaging/tests/test_util.py b/Lib/packaging/tests/test_util.py
index 737503e..7f7ed18 100644
--- a/Lib/packaging/tests/test_util.py
+++ b/Lib/packaging/tests/test_util.py
@@ -173,6 +173,11 @@
         sys.stdout = self.old_stdout
         sys.stderr = self.old_stderr
 
+    def test_set_platform(self):
+        self.addCleanup(util.set_platform, util.get_platform())
+        util.set_platform("fake")
+        self.assertEqual("fake", util.get_platform())
+
     def test_convert_path(self):
         # linux/mac
         os.sep = '/'