diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 32e8b8a3f..d4c6c4c8e 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -63,12 +63,13 @@ def start_worker_reactor(appname, config):
 
     start_reactor(
         appname,
-        config.soft_file_limit,
-        config.gc_thresholds,
-        config.worker_pid_file,
-        config.worker_daemonize,
-        config.worker_cpu_affinity,
-        logger,
+        soft_file_limit=config.soft_file_limit,
+        gc_thresholds=config.gc_thresholds,
+        pid_file=config.worker_pid_file,
+        daemonize=config.worker_daemonize,
+        cpu_affinity=config.worker_cpu_affinity,
+        print_pidfile=config.print_pidfile,
+        logger=logger,
     )
 
 
@@ -79,6 +80,7 @@ def start_reactor(
         pid_file,
         daemonize,
         cpu_affinity,
+        print_pidfile,
         logger,
 ):
     """ Run the reactor in the main process
@@ -93,6 +95,7 @@ def start_reactor(
         pid_file (str): name of pid file to write to if daemonize is True
         daemonize (bool): true to run the reactor in a background process
         cpu_affinity (int|None): cpu affinity mask
+        print_pidfile (bool): whether to print the pid file, if daemonize is True
         logger (logging.Logger): logger instance to pass to Daemonize
     """
 
@@ -124,6 +127,9 @@ def start_reactor(
             reactor.run()
 
     if daemonize:
+        if print_pidfile:
+            print(pid_file)
+
         daemon = Daemonize(
             app=appname,
             pid=pid_file,
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index e8b6cc311..ce89d48bf 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -636,17 +636,15 @@ def run(hs):
         # be quite busy the first few minutes
         clock.call_later(5 * 60, start_phone_stats_home)
 
-    if hs.config.daemonize and hs.config.print_pidfile:
-        print(hs.config.pid_file)
-
     _base.start_reactor(
         "synapse-homeserver",
-        hs.config.soft_file_limit,
-        hs.config.gc_thresholds,
-        hs.config.pid_file,
-        hs.config.daemonize,
-        hs.config.cpu_affinity,
-        logger,
+        soft_file_limit=hs.config.soft_file_limit,
+        gc_thresholds=hs.config.gc_thresholds,
+        pid_file=hs.config.pid_file,
+        daemonize=hs.config.daemonize,
+        cpu_affinity=hs.config.cpu_affinity,
+        print_pidfile=hs.config.print_pidfile,
+        logger=logger,
     )
 
 
diff --git a/synapse/config/workers.py b/synapse/config/workers.py
index 8dc013d0e..bfbd8b6c9 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -28,7 +28,7 @@ class WorkerConfig(Config):
         if self.worker_app == "synapse.app.homeserver":
             self.worker_app = None
 
-        self.worker_listeners = config.get("worker_listeners")
+        self.worker_listeners = config.get("worker_listeners", [])
         self.worker_daemonize = config.get("worker_daemonize")
         self.worker_pid_file = config.get("worker_pid_file")
         self.worker_log_file = config.get("worker_log_file")
@@ -48,6 +48,17 @@ class WorkerConfig(Config):
         self.worker_main_http_uri = config.get("worker_main_http_uri", None)
         self.worker_cpu_affinity = config.get("worker_cpu_affinity")
 
+        # This option is really only here to support `--manhole` command line
+        # argument.
+        manhole = config.get("worker_manhole")
+        if manhole:
+            self.worker_listeners.append({
+                "port": manhole,
+                "bind_addresses": ["127.0.0.1"],
+                "type": "manhole",
+                "tls": False,
+            })
+
         if self.worker_listeners:
             for listener in self.worker_listeners:
                 bind_address = listener.pop("bind_address", None)
@@ -59,5 +70,16 @@ class WorkerConfig(Config):
                     bind_addresses.append('')
 
     def read_arguments(self, args):
+        # We support a bunch of command line arguments that override options in
+        # the config. A lot of these options have a worker_* prefix when running
+        # on workers so we also have to override them when command line options
+        # are specified.
+
         if args.daemonize is not None:
             self.worker_daemonize = args.daemonize
+        if args.log_config is not None:
+            self.worker_log_config = args.log_config
+        if args.log_file is not None:
+            self.worker_log_file = args.log_file
+        if args.manhole is not None:
+            self.worker_manhole = args.worker_manhole