diff --git a/src/Issue/IssueField.php b/src/Issue/IssueField.php
index 0bd2925..085e538 100644
--- a/src/Issue/IssueField.php
+++ b/src/Issue/IssueField.php
@@ -147,6 +147,11 @@ public function jsonSerialize()
             unset($vars['duedateString']);
         }
 
+        if (!empty($this->timeTracking)) {
+            $vars['timetracking'] = $this->timeTracking;
+            unset($vars['timeTracking']);
+        }
+
         return $vars;
     }