diff -r c64216addd7f Lib/test/test_uuid.py
--- a/Lib/test/test_uuid.py	Mon Aug 22 11:55:57 2011 +1000
+++ b/Lib/test/test_uuid.py	Mon Aug 22 16:41:04 2011 +1000
@@ -419,13 +419,7 @@
             equal(u, uuid.UUID(v))
             equal(str(u), v)
 
-    def test_uuid4(self):
-        # uuid4 requires ctypes.
-        try:
-            import ctypes
-        except ImportError:
-            return
-
+    def uuid4_test_inner(self):
         equal = self.assertEqual
 
         # Make sure uuid4() generates UUIDs that are actually version 4.
@@ -439,6 +433,22 @@
             uuids[u] = 1
         equal(len(uuids.keys()), 1000)
 
+    def test_uuid4_with_ctypes(self):
+        # uuid4 requires ctypes.
+        try:
+            import ctypes
+        except ImportError:
+            return
+        self.uuid4_test_inner()
+
+    def test_uuid4_no_system_routine(self):
+        saved = uuid._uuid_generate_random
+        try:
+            uuid._uuid_generate_random = None
+            self.uuid4_test_inner()
+        finally:
+            uuid._uuid_generate_random = saved
+
     def test_uuid5(self):
         equal = self.assertEqual