diff --git a/src/applications/maniphest/controller/ManiphestTaskEditController.php b/src/applications/maniphest/controller/ManiphestTaskEditController.php
--- a/src/applications/maniphest/controller/ManiphestTaskEditController.php
+++ b/src/applications/maniphest/controller/ManiphestTaskEditController.php
@@ -145,6 +145,15 @@
 
     $aux_fields = $field_list->getFields();
 
+    // Read custom fields request if they are provided
+    if (!$request->isFormPost()) {
+      foreach ($aux_fields as $name => $field) {
+        if ($request->getStr($name)) {
+          $field->readValueFromRequest($request);
+        }
+      }
+    }
+
     if ($request->isFormPost()) {
       $changes = array();