diff --git a/CRM/Case/Form/Activity/LinkCases.php b/CRM/Case/Form/Activity/LinkCases.php
index 466dda292fd8..294b1d03774f 100644
--- a/CRM/Case/Form/Activity/LinkCases.php
+++ b/CRM/Case/Form/Activity/LinkCases.php
@@ -70,7 +70,11 @@ public static function preProcess(&$form) {
    * @return array
    */
   public static function setDefaultValues(&$form) {
-    return $defaults = array();
+    $defaults = array();
+    if (!empty($_GET['link_to_case_id']) && CRM_Utils_Rule::positiveInteger($_GET['link_to_case_id'])) {
+      $defaults['link_to_case_id'] = $_GET['link_to_case_id'];
+    }
+    return $defaults;
   }
 
   /**