diff --git a/pipe_io_server/pipe_reader_thread.py b/pipe_io_server/pipe_reader_thread.py
index 85e9a2e..7e16b32 100644
--- a/pipe_io_server/pipe_reader_thread.py
+++ b/pipe_io_server/pipe_reader_thread.py
@@ -34,11 +34,13 @@ class PipeReaderThread(Thread):
         return open(self._pipe_path, 'rb')
 
     def stop(self):
-        self.unblock()
+        self._unblock()
         self.join()
 
-    def unblock(self):
-        with suppress(OSError):
-            fd = osopen(self._pipe_path, O_WRONLY | O_NONBLOCK)
-            write(fd, self.stop_sequence)
-            close(fd)
+    def _unblock(self):
+        while True:
+            with suppress(OSError):
+                fd = osopen(self._pipe_path, O_WRONLY | O_NONBLOCK)
+                write(fd, self.stop_sequence)
+                close(fd)
+                break
diff --git a/pipe_io_server/pipe_writer_thread.py b/pipe_io_server/pipe_writer_thread.py
index 3be90f9..054496d 100644
--- a/pipe_io_server/pipe_writer_thread.py
+++ b/pipe_io_server/pipe_writer_thread.py
@@ -39,11 +39,13 @@ class PipeWriterThread(Thread):
         return open(self._pipe_path, 'wb')
 
     def stop(self):
-        self.unblock()
+        self._unblock()
         self.join()
 
-    def unblock(self):
-        self._write_queue.push_front(None)
-        with suppress(OSError):
-            fd = osopen(self._pipe_path, O_RDONLY | O_NONBLOCK)
-            close(fd)
+    def _unblock(self):
+        while True:
+            with suppress(OSError):
+                fd = osopen(self._pipe_path, O_RDONLY | O_NONBLOCK)
+                self._write_queue.push_front(None)
+                close(fd)
+                break