diff --git a/app/controllers/api/functions.php b/app/controllers/api/functions.php
index b2d7ecc614..2aba77043e 100644
--- a/app/controllers/api/functions.php
+++ b/app/controllers/api/functions.php
@@ -477,7 +477,7 @@ App::post('/v1/functions/:functionId/tags')
             } else {
                 // Calculate total number of chunks based on the chunk size i.e ($rangeEnd - $rangeStart)
                 $chunks = (int) ceil($size / ($end + 1 - $start));
-                $chunk = (int) ($start / ($end + 1 - $start));
+                $chunk = (int) ($start / ($end + 1 - $start)) + 1;
             }
         }
 
@@ -498,7 +498,7 @@ App::post('/v1/functions/:functionId/tags')
         if(!$tag->isEmpty()) {
             $chunks = $tag->getAttribute('chunksTotal', 1);
             if($chunk == -1) {
-                $chunk = $chunks - 1;
+                $chunk = $chunks;
             }
         }