diff --git a/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/dpt/KNXCoreTypeMapper.java b/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/dpt/KNXCoreTypeMapper.java
index 66a5ae475..db902650a 100644
--- a/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/dpt/KNXCoreTypeMapper.java
+++ b/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/dpt/KNXCoreTypeMapper.java
@@ -888,7 +888,7 @@ public class KNXCoreTypeMapper implements KNXTypeMapper {
                     DPTXlator3BitControlled translator3BitControlled = (DPTXlator3BitControlled) translator;
                     if (translator3BitControlled.getStepCode() == 0) {
                         logger.debug("toType: KNX DPT_Control_Dimming: break received.");
-                        return UnDefType.UNDEF;
+                        return UnDefType.NULL;
                     }
                     switch (subNumber) {
                         case 7:
@@ -897,6 +897,7 @@ public class KNXCoreTypeMapper implements KNXTypeMapper {
                         case 8:
                             return translator3BitControlled.getControlBit() ? UpDownType.DOWN : UpDownType.UP;
                     }
+                    break;
                 case 18:
                     DPTXlatorSceneControl translatorSceneControl = (DPTXlatorSceneControl) translator;
                     int decimalValue = translatorSceneControl.getSceneNumber();
diff --git a/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/handler/DeviceThingHandler.java b/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/handler/DeviceThingHandler.java
index aecce6bce..68d5c74b7 100644
--- a/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/handler/DeviceThingHandler.java
+++ b/bundles/org.openhab.binding.knx/src/main/java/org/openhab/binding/knx/internal/handler/DeviceThingHandler.java
@@ -413,7 +413,7 @@ public class DeviceThingHandler extends AbstractKNXThingHandler {
                     }
                 }
             } else {
-                if (type instanceof State) {
+                if (type instanceof State && !(type instanceof UnDefType)) {
                     updateState(channelUID, (State) type);
                 }
             }