diff --git a/package.json b/package.json
index 8a0966d..ff134f5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "node-red-contrib-iiot-opcua",
-  "version": "4.1.1",
+  "version": "4.1.2",
   "description": "An Industrial IoT OPC UA toolbox contribution package for Node-RED based on node-opcua.",
   "repository": {
     "type": "git",
diff --git a/src/core/opcua-iiot-core.ts b/src/core/opcua-iiot-core.ts
index 6bdd197..b720a4b 100644
--- a/src/core/opcua-iiot-core.ts
+++ b/src/core/opcua-iiot-core.ts
@@ -656,7 +656,7 @@ export function normalizeMessage(msg: WriteMessage) {
 
   if (!isNotDefined(writeValues)) {
     return addressSpaceValues.map((item, index) => {
-      return {...item, value: writeValues[index] || ''}
+      return {...item, value: _.isUndefined(writeValues[index]) ? null : writeValues[index]}
     })
   } else
     return addressSpaceValues.map((item, index) => {
diff --git a/test/e2e/opcua-iiot-flex-server.test.js b/test/e2e/opcua-iiot-flex-server.test.js
index 06e7992..cfaf396 100644
--- a/test/e2e/opcua-iiot-flex-server.test.js
+++ b/test/e2e/opcua-iiot-flex-server.test.js
@@ -91,6 +91,8 @@ describe("OPC UA Flex Server Node E2E testing", () => {
           expect(msg.payload.value[0].statusCode).toBeDefined()
           expect(msg.payload.value[0].statusCode.value).toBe(0)
           expect(msg.payload.value[0].value?.value).toBeDefined()
+          expect(msg.payload.value[0].value?.value).toBe(0)
+          expect(msg.payload.value[0].value?.dataType).toBe("Double")
           expect(msg.payload.injectType).toBe("read")
           done()
         })