diff --git a/gdb/python/lib/gdb/dap/io.py b/gdb/python/lib/gdb/dap/io.py
index 4edd504..81e835c 100644
--- a/gdb/python/lib/gdb/dap/io.py
+++ b/gdb/python/lib/gdb/dap/io.py
@@ -79,4 +79,4 @@
             stream.write(body_bytes)
             stream.flush()
 
-    start_thread("JSON writer", _json_writer)
+    return start_thread("JSON writer", _json_writer)
diff --git a/gdb/python/lib/gdb/dap/server.py b/gdb/python/lib/gdb/dap/server.py
index 7cc5a46..e711066 100644
--- a/gdb/python/lib/gdb/dap/server.py
+++ b/gdb/python/lib/gdb/dap/server.py
@@ -212,7 +212,7 @@
         # Before looping, start the thread that writes JSON to the
         # client, and the thread that reads output from the inferior.
         start_thread("output reader", self._read_inferior_output)
-        start_json_writer(self.out_stream, self.write_queue)
+        json_writer = start_json_writer(self.out_stream, self.write_queue)
         start_thread("JSON reader", self._reader_thread)
         while not self.done:
             cmd = self.read_queue.get()
@@ -229,6 +229,7 @@
         # JSON-writing thread, so that we can ensure that all
         # responses are flushed to the client before exiting.
         self.write_queue.put(None)
+        json_writer.join()
 
     @in_dap_thread
     def send_event_later(self, event, body=None):
diff --git a/gdb/python/lib/gdb/dap/startup.py b/gdb/python/lib/gdb/dap/startup.py
index 6049121..0a42c91 100644
--- a/gdb/python/lib/gdb/dap/startup.py
+++ b/gdb/python/lib/gdb/dap/startup.py
@@ -80,6 +80,7 @@
 
     result = gdb.Thread(name=name, target=thread_wrapper, args=args, daemon=True)
     result.start()
+    return result
 
 
 def start_dap(target):