diff --git a/src/node-red/subscriptionNode.js b/src/node-red/subscriptionNode.js
index bb8c96733033019266c4b5cbe6bacd0c59b7a200..ca54477ee634162f3e89fed011b26862b9ac198f 100644
--- a/src/node-red/subscriptionNode.js
+++ b/src/node-red/subscriptionNode.js
@@ -101,7 +101,7 @@ module.exports = function (RED) {
                     'headers': {
                         'X-M2M-RI': ri,
                         'X-M2M-Origin': adminOriginator,
-                        "X-M2M-RVI": "3",
+                        'X-M2M-RVI': '3',
                         'accept': 'application/json',
                         'content-type': 'application/json;ty=23'
                     },