diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 6272758..5220891 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -385,6 +385,46 @@
         self.addCleanup(p.stdout.close)
         self.assertEqual(p.stdout.read(), "orange")
 
+    def test_invalid_cmd(self):
+        # null character in the command name
+        cmd = sys.executable + '\0'
+        with self.assertRaises(TypeError):
+            subprocess.Popen([cmd, "-c", "pass"])
+
+        # null character in the command argument
+        with self.assertRaises(TypeError):
+            subprocess.Popen([sys.executable, "-c", "pass#\0"])
+
+    def test_invalid_env(self):
+        # null character in the enviroment variable name
+        newenv = os.environ.copy()
+        newenv["FRUIT\0VEGETABLE"] = "cabbage"
+        with self.assertRaises(TypeError):
+            subprocess.Popen([sys.executable, "-c", "pass"], env=newenv)
+
+        # null character in the enviroment variable value
+        newenv = os.environ.copy()
+        newenv["FRUIT"] = "orange\0VEGETABLE=cabbage"
+        with self.assertRaises(TypeError):
+            subprocess.Popen([sys.executable, "-c", "pass"], env=newenv)
+
+        # equal character in the enviroment variable name
+        newenv = os.environ.copy()
+        newenv["FRUIT=ORANGE"] = "lemon"
+        with self.assertRaises(ValueError):
+            subprocess.Popen([sys.executable, "-c", "pass"], env=newenv)
+
+        # equal character in the enviroment variable value
+        newenv = os.environ.copy()
+        newenv["FRUIT"] = "orange=lemon"
+        p = subprocess.Popen([sys.executable, "-c",
+                              'import sys, os;'
+                              'sys.stdout.write(os.getenv("FRUIT"))'],
+                             stdout=subprocess.PIPE,
+                             env=newenv)
+        stdout, stderr = p.communicate()
+        self.assertEqual(stdout, "orange=lemon")
+
     def test_communicate_stdin(self):
         p = subprocess.Popen([sys.executable, "-c",
                               'import sys;'