diff --git a/artiq/dashboard/waveform.py b/artiq/dashboard/waveform.py
index 3db366e6a..0201b5f34 100644
--- a/artiq/dashboard/waveform.py
+++ b/artiq/dashboard/waveform.py
@@ -684,7 +684,7 @@ class WaveformDock(QtWidgets.QDockWidget):
         self._current_dir = os.getcwd()
 
         self.proxy_client = WaveformProxyClient(self._state, loop)
-        devices_sub = Subscriber("devices", self.init_ddb, self.update_ddb)
+        devices_sub = Subscriber("devices", self.init_ddb)
 
         proxy_receiver = comm_analyzer.AnalyzerProxyReceiver(
             self.on_dump_receive)
@@ -852,12 +852,9 @@ class WaveformDock(QtWidgets.QDockWidget):
     # DeviceDB subscriber callbacks
     def init_ddb(self, ddb):
         self._ddb = ddb
-
-    def update_ddb(self, mod):
-        devices = self._ddb
         addr = None
-        self._channels_mgr.init(comm_analyzer.get_channel_list(devices))
-        for name, desc in devices.items():
+        self._channels_mgr.init(comm_analyzer.get_channel_list(ddb))
+        for name, desc in ddb.items():
             if isinstance(desc, dict):
                 if desc["type"] == "controller" and name == "core_analyzer":
                     addr = desc["host"]
@@ -865,3 +862,4 @@ class WaveformDock(QtWidgets.QDockWidget):
                     port_control = desc.get("port_proxy_control", 1386)
         if addr is not None:
             self.proxy_client.update_address(addr, port, port_control)
+        return ddb