diff --git a/src/bitmessagemain.py b/src/bitmessagemain.py
index 91032fe5..6f796939 100755
--- a/src/bitmessagemain.py
+++ b/src/bitmessagemain.py
@@ -342,13 +342,21 @@ class Main:
                 sleep(1)
 
     def daemonize(self):
+        grandfatherPid = os.getpid()
+        parentPid = None
         try:
             if os.fork():
+                # unlock
+                shared.thisapp.cleanup()
+                # wait until grandchild ready
+                while True:
+                    sleep(1)
                 os._exit(0)
         except AttributeError:
             # fork not implemented
             pass
         else:
+            parentPid = os.getpid()
             shared.thisapp.lock() # relock
         os.umask(0)
         try:
@@ -358,12 +366,17 @@ class Main:
             pass
         try:
             if os.fork():
+                # unlock
+                shared.thisapp.cleanup()
+                # wait until child ready
+                while True:
+                    sleep(1)
                 os._exit(0)
         except AttributeError:
             # fork not implemented
             pass
         else:
-            shared.thisapp.lock(True) # relock and write pid
+            shared.thisapp.lock() # relock
         shared.thisapp.lockPid = None # indicate we're the final child
         sys.stdout.flush()
         sys.stderr.flush()
@@ -374,6 +387,10 @@ class Main:
             os.dup2(si.fileno(), sys.stdin.fileno())
             os.dup2(so.fileno(), sys.stdout.fileno())
             os.dup2(se.fileno(), sys.stderr.fileno())
+        if parentPid:
+            # signal ready
+            os.kill(parentPid, signal.SIGTERM)
+            os.kill(grandfatherPid, signal.SIGTERM)
 
     def setSignalHandler(self):
         signal.signal(signal.SIGINT, helper_generic.signal_handler)
diff --git a/src/helper_generic.py b/src/helper_generic.py
index b750e519..4f7a1299 100644
--- a/src/helper_generic.py
+++ b/src/helper_generic.py
@@ -51,7 +51,7 @@ def signal_handler(signal, frame):
         raise SystemExit
     if "PoolWorker" in current_process().name:
         raise SystemExit
-    if current_thread().name != "PyBitmessage":
+    if current_thread().name not in ("PyBitmessage", "MainThread"):
         return
     logger.error("Got signal %i", signal)
     if BMConfigParser().safeGetBoolean('bitmessagesettings', 'daemon'):
diff --git a/src/singleinstance.py b/src/singleinstance.py
index fdb5ee98..d7cc0ab3 100644
--- a/src/singleinstance.py
+++ b/src/singleinstance.py
@@ -36,7 +36,7 @@ class singleinstance:
         self.initialized = True
         atexit.register(self.cleanup)
 
-    def lock(self, writePid = False):
+    def lock(self):
         if self.lockPid is None:
             self.lockPid = os.getpid()
         if sys.platform == 'win32':
@@ -68,16 +68,24 @@ class singleinstance:
                 sys.exit(-1)
             else:
                 pidLine = "%i\n" % self.lockPid
-                if writePid:
-                    self.fp.truncate(0)
-                    self.fp.write(pidLine)
-                    self.fp.flush()
+                self.fp.truncate(0)
+                self.fp.write(pidLine)
+                self.fp.flush()
 
     def cleanup(self):
         if not self.initialized:
             return
         if self.daemon and self.lockPid == os.getpid():
             # these are the two initial forks while daemonizing
+            try:
+                if sys.platform == 'win32':
+                    if hasattr(self, 'fd'):
+                        os.close(self.fd)
+                else:
+                    fcntl.lockf(self.fp, fcntl.LOCK_UN)
+            except Exception, e:
+                pass
+
             return
         print "Cleaning up lockfile"
         try: