diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index 12f77a9..c8d0c7e 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -64,8 +64,27 @@
         self.assertEqual(list(d), [7, 8, 9])
         d = deque(range(200), maxlen=10)
         d.append(d)
+        fo = open(test_support.TESTFN, "w")
+        try:
+            fo.write(str(d))
+            fo.close()
+            fo = open(test_support.TESTFN, "r")
+            self.assertEqual(fo.read(), repr(d))
+        finally:
+            fo.close()
+            test_support.unlink(test_support.TESTFN)
+
         d = deque(range(10), maxlen=None)
         self.assertEqual(repr(d), 'deque([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])')
+        fo = open(test_support.TESTFN, "w")
+        try:
+            fo.write(str(d))
+            fo.close()
+            fo = open(test_support.TESTFN, "r")
+            self.assertEqual(fo.read(), repr(d))
+        finally:
+            fo.close()
+            test_support.unlink(test_support.TESTFN)
 
     def test_comparisons(self):
         d = deque('xabc'); d.popleft()
@@ -265,13 +284,13 @@
         d.append(d)
         try:
             fo = open(test_support.TESTFN, "w")
-            fo.write(str(d))
+            print(d, file=fo, end='')
             fo.close()
             fo = open(test_support.TESTFN, "r")
             self.assertEqual(fo.read(), repr(d))
         finally:
             fo.close()
-            os.remove(test_support.TESTFN)
+            test_support.unlink(test_support.TESTFN)
 
     def test_init(self):
         self.assertRaises(TypeError, deque, 'abc', 2, 3);
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index ca3c02e..44a45af 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -295,7 +295,7 @@
             self.assertEqual(fo.read(), repr(s))
         finally:
             fo.close()
-            os.remove(test_support.TESTFN)
+            test_support.unlink(test_support.TESTFN)
 
     def test_do_not_rehash_dict_keys(self):
         n = 10
@@ -679,7 +679,7 @@
             self.assertEqual(fo.read(), repr(self.set))
         finally:
             fo.close()
-            os.remove(test_support.TESTFN)
+            test_support.unlink(test_support.TESTFN)
 
     def test_length(self):
         self.assertEqual(len(self.set), self.length)
diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
index 2cee626..3c039a1 100644
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -1,6 +1,7 @@
 import unittest
 from test import test_support
 from contextlib import closing, nested
+import gc
 import pickle
 import select
 import signal
@@ -30,6 +31,14 @@
 class InterProcessSignalTests(unittest.TestCase):
     MAX_DURATION = 20   # Entire test should last at most 20 sec.
 
+    def setUp(self):
+        self.using_gc = gc.isenabled()
+        gc.disable()
+
+    def tearDown(self):
+        if self.using_gc:
+            gc.enable()
+
     def handlerA(self, *args):
         self.a_called = True
         if test_support.verbose:
@@ -263,8 +272,10 @@
         self.hndl_called = False
         self.hndl_count = 0
         self.itimer = None
+        self.old_alarm = signal.signal(signal.SIGALRM, self.sig_alrm)
 
     def tearDown(self):
+        signal.signal(signal.SIGALRM, self.old_alarm)
         if self.itimer is not None: # test_itimer_exc doesn't change this attr
             # just ensure that itimer is stopped
             signal.setitimer(self.itimer, 0)
@@ -303,13 +314,13 @@
         # XXX I'm assuming -1 is an invalid itimer, but maybe some platform
         # defines it ?
         self.assertRaises(signal.ItimerError, signal.setitimer, -1, 0)
-        # negative time
-        self.assertRaises(signal.ItimerError, signal.setitimer,
-            signal.ITIMER_REAL, -1)
+        # Negative times are treated as zero on some platforms.
+        if 0:
+            self.assertRaises(signal.ItimerError,
+                              signal.setitimer, signal.ITIMER_REAL, -1)
 
     def test_itimer_real(self):
         self.itimer = signal.ITIMER_REAL
-        signal.signal(signal.SIGALRM, self.sig_alrm)
         signal.setitimer(self.itimer, 1.0)
         if test_support.verbose:
             print("\ncall pause()...")