2 files changed, 7 insertions, 4 deletions
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 5b0ca312e2..1d2c3339ff 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -153,9 +153,8 @@ def listen_metrics(bind_addresses, port):
     from prometheus_client import start_http_server
 
     for host in bind_addresses:
-        reactor.callInThread(start_http_server, int(port),
-                             addr=host, registry=RegistryProxy)
-        logger.info("Metrics now reporting on %s:%d", host, port)
+        logger.info("Starting metrics listener on %s:%d", host, port)
+        start_http_server(port, addr=host, registry=RegistryProxy)
 
 
 def listen_tcp(bind_addresses, port, factory, reactor=reactor, backlog=50):
diff --git a/synapse/config/server.py b/synapse/config/server.py
index c5c3aac8ed..93a30e4cfa 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -151,7 +151,11 @@ class ServerConfig(Config):
 
             # if we still have an empty list of addresses, use the default list
             if not bind_addresses:
-                bind_addresses.extend(DEFAULT_BIND_ADDRESSES)
+                if listener['type'] == 'metrics':
+                    # the metrics listener doesn't support IPv6
+                    bind_addresses.append('0.0.0.0')
+                else:
+                    bind_addresses.extend(DEFAULT_BIND_ADDRESSES)
 
             self.listeners.append(listener)