diff --git a/src/commands/handlers.js b/src/commands/handlers.js
index 32a3ee9..c803948 100644
--- a/src/commands/handlers.js
+++ b/src/commands/handlers.js
@@ -88,9 +88,14 @@ exports.setOutflow = (source, msg) => {
 
 exports.setDemand = (source, msg, ctx) => {
   const log = _logger(source, ctx);
-  const demand = Number(msg.payload);
+  // generalFunctions/commandRegistry's _normaliseUnits has already converted
+  // msg.payload to m3/h (the descriptor's units.default — see
+  // commands/index.js). Accepts {value, unit} objects upstream; we just read
+  // the normalized number here. _manualDemand is stored in m3/h, no further
+  // conversion needed.
+  const demand = Number(msg?.payload);
   if (!Number.isFinite(demand)) {
-    log?.warn?.(`set.demand: invalid Qd value '${msg.payload}'`);
+    log?.warn?.(`set.demand: invalid Qd value '${JSON.stringify(msg?.payload)}'`);
     return;
   }
   if (source.mode !== 'manual') {