diff --git a/lib/converters/genericConverter.js b/lib/converters/genericConverter.js
index 3b39bb95f..1e5b393bd 100644
--- a/lib/converters/genericConverter.js
+++ b/lib/converters/genericConverter.js
@@ -1,3 +1,54 @@
+exports.numericDeviceClasses = [
+    'voltage',
+    'sulphur_dioxide',
+    'carbon_dioxide',
+    'current',
+    'volume_storage',
+    'volume',
+    'ozone',
+    'speed',
+    'atmospheric_pressure',
+    'carbon_monoxide',
+    'aqi',
+    'pm25',
+    'nitrogen_monoxide',
+    'power_factor',
+    'pm1',
+    'precipitation',
+    'volatile_organic_compounds',
+    'humidity',
+    'pressure',
+    'battery',
+    'irradiance',
+    'wind_speed',
+    'pm10',
+    'ph',
+    'reactive_power',
+    'temperature',
+    'precipitation_intensity',
+    'sound_pressure',
+    'data_rate',
+    'frequency',
+    'volatile_organic_compounds_parts',
+    'energy',
+    'apparent_power',
+    'weight',
+    'duration',
+    'gas',
+    'water',
+    'power',
+    'monetary',
+    'signal_strength',
+    'data_size',
+    'energy_storage',
+    'nitrogen_dioxide',
+    'nitrous_oxide',
+    'illuminance',
+    'moisture',
+    'distance'
+];
+
+const numericDeviceClassesIob = exports.numericDeviceClasses.concat(['timestamp']);
 
 exports.iobState2EntityState = function (entity, val, attribute) {
     let type = entity.context.type;
@@ -10,8 +61,8 @@ exports.iobState2EntityState = function (entity, val, attribute) {
         return val ? 'on' : 'off';
     } else if (type === 'binary_sensor') {
         return val ? 'on' : 'off';
-    } else if (typeof val === 'number' && entity.attributes && ['timestamp'].includes(entity.attributes.device_class)) {
-        return val; //do not convert timestamps.
+    } else if (typeof val === 'number' && entity.attributes && numericDeviceClassesIob.includes(entity.attributes.device_class)) {
+        return val; //do not convert timestamps or values that have a unit of measurement..
     } else if (typeof val === 'number' && entity.attributes && ['date'].includes(entity.attributes.device_class)) {
         const dateStr = new Date(val).toDateString(); //convert to date string
         return dateStr === 'Invalid Date' ? 'unknown' : dateStr;
diff --git a/lib/server.js b/lib/server.js
index 61c4b5dcc..3caff4211 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -31,6 +31,7 @@ const entityData             = require('./dataSingleton');
 const bindings               = require('./bindings');
 const getFriendlyName        = require('./entities/friendly_name').getFriendlyName;
 const iobState2EntityState   = require('./converters/genericConverter').iobState2EntityState;
+const NUMERIC_DEVICE_CLASSES = require('./converters/genericConverter').numericDeviceClasses;
 const HistoryModule          = require('./modules/history');
 const ConversationModule = require('./modules/conversation');
 const LogbookModule = require('./modules/logbook');
@@ -2472,6 +2473,9 @@ class WebServer {
                         };
                         ws.send(JSON.stringify(t));
                     });
+            } else if (message.type === 'sensor/numeric_device_classes') {
+                //it seems frontend now asks backend for what device_classes are numeric. Ok. Let's use that. ;-)
+                this._sendResponse(ws, message.id, { numeric_device_classes: NUMERIC_DEVICE_CLASSES });
             } else if (message.type.startsWith('browser_mod')) {
                 await this._browserMod.processBrowserModMessage(ws, message);
             } else if (message.type.startsWith('history/')) {