diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
index 1f15ff7..83ac669 100644
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -438,8 +438,8 @@
         self.assertEqual(self.hndl_called, True)
 
     # Issue 3864, unknown if this affects earlier versions of freebsd also
-    @unittest.skipIf(sys.platform=='freebsd6',
-        'itimer not reliable (does not mix well with threading) on freebsd6')
+    @unittest.skipIf(sys.platform in ('freebsd6', 'netbsd5'),
+        'itimer not reliable (does not mix well with threading) on some BSDs.')
     def test_itimer_virtual(self):
         self.itimer = signal.ITIMER_VIRTUAL
         signal.signal(signal.SIGVTALRM, self.sig_vtalrm)
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index c33c823..a467e0d 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -351,8 +351,10 @@
         # Find one service that exists, then check all the related interfaces.
         # I've ordered this by protocols that have both a tcp and udp
         # protocol, at least for modern Linuxes.
-        if sys.platform in ('linux2', 'freebsd4', 'freebsd5', 'freebsd6',
-                            'freebsd7', 'freebsd8', 'darwin'):
+        if (sys.platform.startswith('linux') or
+            sys.platform.startswith('freebsd') or
+            sys.platform.startswith('netbsd') or
+            sys.platform == 'darwin'):
             # avoid the 'echo' service on this platform, as there is an
             # assumption breaking non-standard port/protocol entry
             services = ('daytime', 'qotd', 'domain')
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 713ea9c..a4a6ed6 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -459,7 +459,8 @@
             return
         # Skip platforms with known problems forking from a worker thread.
         # See http://bugs.python.org/issue3863.
-        if sys.platform in ('freebsd4', 'freebsd5', 'freebsd6', 'os2emx'):
+        if sys.platform in ('freebsd4', 'freebsd5', 'freebsd6', 'netbsd5',
+                           'os2emx'):
             print('Skipping test_3_join_in_forked_from_thread'
                   ' due to known OS bugs on', sys.platform, file=sys.stderr)
             return
diff --git a/Modules/_multiprocessing/multiprocessing.c b/Modules/_multiprocessing/multiprocessing.c
index c584f2b..6858146 100644
--- a/Modules/_multiprocessing/multiprocessing.c
+++ b/Modules/_multiprocessing/multiprocessing.c
@@ -269,8 +269,19 @@
     if (PyType_Ready(&SemLockType) < 0)
         return NULL;
     Py_INCREF(&SemLockType);
-    PyDict_SetItemString(SemLockType.tp_dict, "SEM_VALUE_MAX",
-                         Py_BuildValue("i", SEM_VALUE_MAX));
+    {
+        PyObject *py_sem_value_max;
+        /* Some systems define SEM_VALUE_MAX as an unsigned value that
+         * causes it to be negative when used as an int (NetBSD). */
+        if ((int)(SEM_VALUE_MAX) < 0)
+            py_sem_value_max = PyLong_FromLong(INT_MAX);
+        else
+            py_sem_value_max = PyLong_FromLong(SEM_VALUE_MAX);
+        if (py_sem_value_max == NULL)
+            return NULL;
+        PyDict_SetItemString(SemLockType.tp_dict, "SEM_VALUE_MAX",
+                             py_sem_value_max);
+    }
     PyModule_AddObject(module, "SemLock", (PyObject*)&SemLockType);
 #endif
 
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index f88043c..834fc69 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -379,7 +379,7 @@
 #define SOCKETCLOSE close
 #endif
 
-#if (defined(HAVE_BLUETOOTH_H) || defined(HAVE_BLUETOOTH_BLUETOOTH_H)) && !defined(__NetBSD__)
+#if (defined(HAVE_BLUETOOTH_H) || defined(HAVE_BLUETOOTH_BLUETOOTH_H)) && !defined(__NetBSD__) && !defined(__DragonFly__)
 #define USE_BLUETOOTH 1
 #if defined(__FreeBSD__)
 #define BTPROTO_L2CAP BLUETOOTH_PROTO_L2CAP
@@ -393,11 +393,13 @@
 #define _BT_L2_MEMB(sa, memb) ((sa)->l2cap_##memb)
 #define _BT_RC_MEMB(sa, memb) ((sa)->rfcomm_##memb)
 #define _BT_HCI_MEMB(sa, memb) ((sa)->hci_##memb)
-#elif defined(__NetBSD__)
+#elif defined(__NetBSD__) || defined(__DragonFly__)
 #define sockaddr_l2 sockaddr_bt
 #define sockaddr_rc sockaddr_bt
 #define sockaddr_hci sockaddr_bt
 #define sockaddr_sco sockaddr_bt
+#define SOL_HCI BTPROTO_HCI
+#define HCI_DATA_DIR SO_HCI_DIRECTION
 #define _BT_L2_MEMB(sa, memb) ((sa)->bt_##memb)
 #define _BT_RC_MEMB(sa, memb) ((sa)->bt_##memb)
 #define _BT_HCI_MEMB(sa, memb) ((sa)->bt_##memb)
@@ -1039,9 +1041,13 @@
         case BTPROTO_HCI:
         {
             struct sockaddr_hci *a = (struct sockaddr_hci *) addr;
+#if defined(__NetBSD__) || defined(__DragonFly__)
+            return makebdaddr(&_BT_HCI_MEMB(a, bdaddr));
+#else
             PyObject *ret = NULL;
             ret = Py_BuildValue("i", _BT_HCI_MEMB(a, dev));
             return ret;
+#endif
         }
 
 #if !defined(__FreeBSD__)
@@ -1325,12 +1331,25 @@
         case BTPROTO_HCI:
         {
             struct sockaddr_hci *addr = (struct sockaddr_hci *)addr_ret;
+#if defined(__NetBSD__) || defined(__DragonFly__)
+			char *straddr = PyBytes_AS_STRING(args);
+
+			_BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
+            if (straddr == NULL) {
+                PyErr_SetString(socket_error, "getsockaddrarg: "
+                    "wrong format");
+                return 0;
+            }
+            if (setbdaddr(straddr, &_BT_HCI_MEMB(addr, bdaddr)) < 0)
+                return 0;
+#else
             _BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
             if (!PyArg_ParseTuple(args, "i", &_BT_HCI_MEMB(addr, dev))) {
                 PyErr_SetString(socket_error, "getsockaddrarg: "
                                 "wrong format");
                 return 0;
             }
+#endif
             *len_ret = sizeof *addr;
             return 1;
         }
@@ -4400,9 +4419,13 @@
     PyModule_AddIntConstant(m, "BTPROTO_L2CAP", BTPROTO_L2CAP);
     PyModule_AddIntConstant(m, "BTPROTO_HCI", BTPROTO_HCI);
     PyModule_AddIntConstant(m, "SOL_HCI", SOL_HCI);
+#if !defined(__NetBSD__) && !defined(__DragonFly__)
     PyModule_AddIntConstant(m, "HCI_FILTER", HCI_FILTER);
+#endif
 #if !defined(__FreeBSD__)
+#if !defined(__NetBSD__) && !defined(__DragonFly__)
     PyModule_AddIntConstant(m, "HCI_TIME_STAMP", HCI_TIME_STAMP);
+#endif
     PyModule_AddIntConstant(m, "HCI_DATA_DIR", HCI_DATA_DIR);
     PyModule_AddIntConstant(m, "BTPROTO_SCO", BTPROTO_SCO);
 #endif