diff --git a/libnymea/devices/deviceutils.cpp b/libnymea/devices/deviceutils.cpp
index b2d81572..fdde03d3 100644
--- a/libnymea/devices/deviceutils.cpp
+++ b/libnymea/devices/deviceutils.cpp
@@ -26,6 +26,7 @@
 #include <QDir>
 #include <QFileInfo>
 #include <QJsonParseError>
+#include <QMetaEnum>
 
 DeviceUtils::DeviceUtils()
 {
@@ -191,6 +192,15 @@ Interface DeviceUtils::loadInterface(const QString &name)
         stateType.setPossibleValues(stateVariant.toMap().value("allowedValues").toList());
         stateType.setMinValue(stateVariant.toMap().value("minValue"));
         stateType.setMaxValue(stateVariant.toMap().value("maxValue"));
+        if (stateVariant.toMap().contains("unit")) {
+            QMetaEnum unitEnum = QMetaEnum::fromType<Types::Unit>();
+            int enumValue = unitEnum.keyToValue("Unit" + stateVariant.toMap().value("unit").toByteArray());
+            if (enumValue == -1) {
+                qCWarning(dcDeviceManager) << "Invalid unit" << stateVariant.toMap().value("unit").toString() << "in interface" << name;
+            } else {
+                stateType.setUnit(static_cast<Types::Unit>(unitEnum.keyToValue("Unit" + stateVariant.toMap().value("unit").toByteArray())));
+            }
+        }
         stateTypes.append(stateType);
 
         EventType stateChangeEventType;
diff --git a/libnymea/devices/pluginmetadata.cpp b/libnymea/devices/pluginmetadata.cpp
index 75aded84..7f000464 100644
--- a/libnymea/devices/pluginmetadata.cpp
+++ b/libnymea/devices/pluginmetadata.cpp
@@ -594,6 +594,12 @@ void PluginMetadata::parse(const QJsonObject &jsonObject)
                         hasError = true;
                         continue;
                     }
+                    if (ifaceStateType.unit() != Types::UnitNone && ifaceStateType.unit() != stateType.unit()) {
+                        QMetaEnum unitEnum = QMetaEnum::fromType<Types::Unit>();
+                        m_validationErrors.append("Device class \"" + deviceClass.name() + "\" claims to implement interface \"" + value.toString() + "\" but state \"" + stateType.name() + "\" has not matching unit: \"" + unitEnum.valueToKey(ifaceStateType.unit()) + "\" != \"" + unitEnum.valueToKey(stateType.unit()));
+                        hasError = true;
+                        continue;
+                    }
                 }
 
                 foreach (const ActionType &ifaceActionType, iface.actionTypes()) {
diff --git a/libnymea/interfaces/conductivitysensor.json b/libnymea/interfaces/conductivitysensor.json
index 088099fa..d1d9e63c 100644
--- a/libnymea/interfaces/conductivitysensor.json
+++ b/libnymea/interfaces/conductivitysensor.json
@@ -4,7 +4,7 @@
         {
             "name": "conductivity",
             "type": "double",
-            "unit": "UnitMicroSiemensPerCentimeter"
+            "unit": "MicroSiemensPerCentimeter"
         }
     ]
 }
diff --git a/libnymea/interfaces/extendedsmartmeterconsumer.json b/libnymea/interfaces/extendedsmartmeterconsumer.json
index bca5393a..f476bd9e 100644
--- a/libnymea/interfaces/extendedsmartmeterconsumer.json
+++ b/libnymea/interfaces/extendedsmartmeterconsumer.json
@@ -4,7 +4,8 @@
     "states": [
         {
             "name": "currentPower",
-            "type": "double"
+            "type": "double",
+            "unit": "Watt"
         }
     ]
 }
diff --git a/libnymea/interfaces/smartmeterconsumer.json b/libnymea/interfaces/smartmeterconsumer.json
index b44c85c9..8ecffc4f 100644
--- a/libnymea/interfaces/smartmeterconsumer.json
+++ b/libnymea/interfaces/smartmeterconsumer.json
@@ -4,7 +4,8 @@
     "states": [
         {
             "name": "totalEnergyConsumed",
-            "type": "double"
+            "type": "double",
+            "unit": "KiloWattHour"
         }
     ]
 }