diff --git a/devices/protocols/ZwaveJS/xaal/zwavejs/devices.py b/devices/protocols/ZwaveJS/xaal/zwavejs/devices.py
index 62dd1b06ecba2f6f95c3192277ab6b73361fffa3..d79045730e0cb65894f4565c321239ad704a04f4 100644
--- a/devices/protocols/ZwaveJS/xaal/zwavejs/devices.py
+++ b/devices/protocols/ZwaveJS/xaal/zwavejs/devices.py
@@ -41,7 +41,7 @@ def build_devices(node: Node, eng: AsyncEngine):
     # node.on("value updated", self.value_updated)
     # pdb.set_trace()
     #
-
+    assert BASE_ADDR
     base_addr = BASE_ADDR + node.node_id * 128
     for k in node.values:
         value = node.values.get(k)