diff --git a/electrum/interface.py b/electrum/interface.py
index da2e08ad8..1d165f6f0 100644
--- a/electrum/interface.py
+++ b/electrum/interface.py
@@ -54,7 +54,7 @@ class NotificationSession(ClientSession):
         # will catch the exception, count errors, and at some point disconnect
         if isinstance(request, Notification):
             params, result = request.args[:-1], request.args[-1]
-            key = request.method + repr(params)
+            key = self.get_index(request.method, params)
             if key in self.subscriptions:
                 self.cache[key] = result
                 for queue in self.subscriptions[key]:
@@ -70,7 +70,7 @@ class NotificationSession(ClientSession):
             timeout)
 
     async def subscribe(self, method, params, queue):
-        key = method + repr(params)
+        key = self.get_index(method, params)
         if key in self.subscriptions:
             self.subscriptions[key].append(queue)
             result = self.cache[key]
@@ -88,6 +88,11 @@ class NotificationSession(ClientSession):
             if queue in v:
                 v.remove(queue)
 
+    @classmethod
+    def get_index(cls, method, params):
+        """Hashable index for subscriptions and cache"""
+        return str(method) + repr(params)
+
 
 # FIXME this is often raised inside a TaskGroup, but then it's not silent :(
 class GracefulDisconnect(AIOSafeSilentException): pass
diff --git a/electrum/network.py b/electrum/network.py
index 20ebde59a..06d33935f 100644
--- a/electrum/network.py
+++ b/electrum/network.py
@@ -598,11 +598,6 @@ class Network(PrintError):
         self.recent_servers = self.recent_servers[0:20]
         self.save_recent_servers()
 
-    @classmethod
-    def get_index(cls, method, params):
-        """ hashable index for subscriptions and cache"""
-        return str(method) + (':' + str(params[0]) if params else '')
-
     @with_interface_lock
     def connection_down(self, server):
         '''A connection to server either went down, or was never made.