diff --git a/contrib/plugins/helloworld.py b/contrib/plugins/helloworld.py
index e7987329c..d74b96627 100755
--- a/contrib/plugins/helloworld.py
+++ b/contrib/plugins/helloworld.py
@@ -20,22 +20,22 @@ def hello(plugin, name="world"):
 
 
 @plugin.init()
-def init(options, configuration, plugin):
+def init(options, configuration, plugin, **kwargs):
     plugin.log("Plugin helloworld.py initialized")
 
 
 @plugin.subscribe("connect")
-def on_connect(plugin, id, address):
+def on_connect(plugin, id, address, **kwargs):
     plugin.log("Received connect event for peer {}".format(id))
 
 
 @plugin.subscribe("disconnect")
-def on_disconnect(plugin, id):
+def on_disconnect(plugin, id, **kwargs):
     plugin.log("Received disconnect event for peer {}".format(id))
 
 
 @plugin.subscribe("invoice_payment")
-def on_payment(plugin, invoice_payment):
+def on_payment(plugin, invoice_payment, **kwargs):
     plugin.log("Received invoice_payment event for label {}, preimage {},"
                " and amount of {}".format(invoice_payment.get("label"),
                                           invoice_payment.get("preimage"),
@@ -43,7 +43,7 @@ def on_payment(plugin, invoice_payment):
 
 
 @plugin.hook("htlc_accepted")
-def on_htlc_accepted(onion, htlc, plugin):
+def on_htlc_accepted(onion, htlc, plugin, **kwargs):
     plugin.log('on_htlc_accepted called')
     time.sleep(20)
     return {'result': 'continue'}
diff --git a/contrib/pylightning/lightning/plugin.py b/contrib/pylightning/lightning/plugin.py
index 038f9d256..ab2c288a9 100644
--- a/contrib/pylightning/lightning/plugin.py
+++ b/contrib/pylightning/lightning/plugin.py
@@ -183,6 +183,19 @@ class Plugin(object):
             raise ValueError(
                 "Topic {} already has a handler".format(topic)
             )
+
+        # Make sure the notification callback has a **kwargs argument so that it
+        # doesn't break if we add more arguments to the call later on. Issue a
+        # warning if it does not.
+        s = inspect.signature(func)
+        kinds = [p.kind for p in s.parameters.values()]
+        if inspect.Parameter.VAR_KEYWORD not in kinds:
+            self.log(
+                "Notification handler {} for notification {} does not have a "
+                "variable keyword argument. It is strongly suggested to add "
+                "`**kwargs` as last parameter to hook and notification "
+                "handlers.".format(func.__name__, topic), level="warn")
+
         self.subscriptions[topic] = func
 
     def subscribe(self, topic):
@@ -251,6 +264,19 @@ class Plugin(object):
             raise ValueError(
                 "Method {} was already registered".format(name, self.methods[name])
             )
+
+        # Make sure the hook callback has a **kwargs argument so that it
+        # doesn't break if we add more arguments to the call later on. Issue a
+        # warning if it does not.
+        s = inspect.signature(func)
+        kinds = [p.kind for p in s.parameters.values()]
+        if inspect.Parameter.VAR_KEYWORD not in kinds:
+            self.log(
+                "Hook handler {} for hook {} does not have a variable keyword "
+                "argument. It is strongly suggested to add `**kwargs` as last "
+                "parameter to hook and notification handlers.".format(
+                    func.__name__, name), level="warn")
+
         method = Method(name, func, MethodType.HOOK)
         method.background = background
         self.methods[name] = method
diff --git a/tests/plugins/dblog.py b/tests/plugins/dblog.py
index 1cf601075..2b985958a 100755
--- a/tests/plugins/dblog.py
+++ b/tests/plugins/dblog.py
@@ -24,7 +24,7 @@ def init(configuration, options, plugin):
 
 
 @plugin.hook('db_write')
-def db_write(plugin, writes):
+def db_write(plugin, writes, **kwargs):
     if not plugin.initted:
         plugin.log("deferring {} commands".format(len(writes)))
         plugin.sqlite_pre_init_cmds += writes
diff --git a/tests/plugins/fail_htlcs.py b/tests/plugins/fail_htlcs.py
index b925dff54..67cde7ce1 100755
--- a/tests/plugins/fail_htlcs.py
+++ b/tests/plugins/fail_htlcs.py
@@ -6,7 +6,7 @@ plugin = Plugin()
 
 
 @plugin.hook("htlc_accepted")
-def on_htlc_accepted(htlc, onion, plugin):
+def on_htlc_accepted(onion, plugin, **kwargs):
     plugin.log("Failing htlc on purpose")
     plugin.log("onion: %r" % (onion))
     return {"result": "fail", "failure_code": 16399}
diff --git a/tests/plugins/hold_htlcs.py b/tests/plugins/hold_htlcs.py
index 3e4a1008a..0533b1b2a 100755
--- a/tests/plugins/hold_htlcs.py
+++ b/tests/plugins/hold_htlcs.py
@@ -17,7 +17,7 @@ plugin = Plugin()
 
 
 @plugin.hook("htlc_accepted")
-def on_htlc_accepted(htlc, onion, plugin):
+def on_htlc_accepted(htlc, onion, plugin, **kwargs):
     # Stash the onion so the test can check it
     fname = os.path.join(tempfile.mkdtemp(), "onion.json")
     with open(fname, 'w') as f:
diff --git a/tests/plugins/hold_invoice.py b/tests/plugins/hold_invoice.py
index ec11d18bf..ebdcf418c 100755
--- a/tests/plugins/hold_invoice.py
+++ b/tests/plugins/hold_invoice.py
@@ -9,7 +9,7 @@ plugin = Plugin()
 
 
 @plugin.hook('invoice_payment')
-def on_payment(payment, plugin):
+def on_payment(payment, plugin, **kwargs):
     time.sleep(float(plugin.get_option('holdtime')))
     return {}
 
diff --git a/tests/plugins/pretend_badlog.py b/tests/plugins/pretend_badlog.py
index 854ec6c3c..23c7ec877 100755
--- a/tests/plugins/pretend_badlog.py
+++ b/tests/plugins/pretend_badlog.py
@@ -12,7 +12,7 @@ def init(configuration, options, plugin):
 
 
 @plugin.subscribe("warning")
-def notify_warning(plugin, warning):
+def notify_warning(plugin, warning, **kwargs):
     plugin.log("Received warning")
     plugin.log("level: {}".format(warning['level']))
     plugin.log("time: {}".format(warning['time']))
diff --git a/tests/plugins/reject.py b/tests/plugins/reject.py
index 64f9c4ff4..da39519ee 100755
--- a/tests/plugins/reject.py
+++ b/tests/plugins/reject.py
@@ -13,7 +13,7 @@ plugin = Plugin()
 
 
 @plugin.hook('peer_connected')
-def on_connected(peer, plugin):
+def on_connected(peer, plugin, **kwargs):
     if peer['id'] in plugin.reject_ids:
         print("{} is in reject list, disconnecting".format(peer['id']))
         return {'result': 'disconnect', 'error_message': 'You are in reject list'}
diff --git a/tests/plugins/reject_odd_funding_amounts.py b/tests/plugins/reject_odd_funding_amounts.py
index 76c295da2..6dc5dc310 100755
--- a/tests/plugins/reject_odd_funding_amounts.py
+++ b/tests/plugins/reject_odd_funding_amounts.py
@@ -10,7 +10,7 @@ plugin = Plugin()
 
 
 @plugin.hook('openchannel')
-def on_openchannel(openchannel, plugin):
+def on_openchannel(openchannel, plugin, **kwargs):
     print("{} VARS".format(len(openchannel.keys())))
     for k in sorted(openchannel.keys()):
         print("{}={}".format(k, openchannel[k]))
diff --git a/tests/plugins/reject_some_invoices.py b/tests/plugins/reject_some_invoices.py
index 99ac6103e..c6f8822e9 100755
--- a/tests/plugins/reject_some_invoices.py
+++ b/tests/plugins/reject_some_invoices.py
@@ -10,7 +10,7 @@ plugin = Plugin()
 
 
 @plugin.hook('invoice_payment')
-def on_payment(payment, plugin):
+def on_payment(payment, plugin, **kwargs):
     print("label={}".format(payment['label']))
     print("msat={}".format(payment['msat']))
     print("preimage={}".format(payment['preimage']))
diff --git a/tests/plugins/shortcircuit.py b/tests/plugins/shortcircuit.py
index 3696c721f..8403b68ec 100755
--- a/tests/plugins/shortcircuit.py
+++ b/tests/plugins/shortcircuit.py
@@ -6,7 +6,7 @@ plugin = Plugin()
 
 
 @plugin.hook("htlc_accepted")
-def on_htlc_accepted(onion, htlc, plugin):
+def on_htlc_accepted(onion, htlc, plugin, **kwargs):
     return {"result": "resolve", "payment_key": "00" * 32}