diff --git a/index.js b/index.js
index e89933626e09e7523dfd155f77a93efeea29802c..e5d11c99b72f2bfaba95e692e2bc61c2bc837c5e 100644
--- a/index.js
+++ b/index.js
@@ -193,7 +193,8 @@ async function getData(token, idPCE, startDate, endDate) {
     })
     .then(result => {
       return result.match(/.+/g).map(s => {
-        result = JSON.parse(s)
+        /** @type {import('./types').GRDFDataRange} */
+        const result = JSON.parse(s)
         if (result.statut_restitution !== null) {
           /**
            * Handle no data issue when retrieving grdf data.