diff --git a/modules/publication/ajax/getData.php b/modules/publication/ajax/getData.php
index 22ed9a6a7a6..adb118b2d97 100644
--- a/modules/publication/ajax/getData.php
+++ b/modules/publication/ajax/getData.php
@@ -20,6 +20,7 @@
 
     if ($action === 'getData') {
         if (userCanGetData($db, $user)) {
+            header('Content-Type: application/json');
             exit(json_encode(getData($db)));
         } else {
             http_response_code(403);
@@ -31,6 +32,7 @@
     } elseif ($action === 'getProjectData') {
         $id = $_REQUEST['id'];
         if (userCanGetData($db, $user, $id)) {
+            header('Content-Type: application/json');
             exit(json_encode(getProjectData($db, $user, $id)));
         } else {
             http_response_code(403);