diff --git a/CRM/Sepa/BAO/SEPATransactionGroup.php b/CRM/Sepa/BAO/SEPATransactionGroup.php
index 2ca7f879..740c59da 100644
--- a/CRM/Sepa/BAO/SEPATransactionGroup.php
+++ b/CRM/Sepa/BAO/SEPATransactionGroup.php
@@ -262,7 +262,7 @@ static function adjustCollectionDate($txgroup_id, $latest_submission_date) {
       return "Bad date adjustment given!";
     }
 
-    $notice_period = (int) CRM_Sepa_Logic_Settings::getSetting("batching.${txgroup['type']}.notice", $txgroup['sdd_creditor_id']);
+    $notice_period = (int) CRM_Sepa_Logic_Settings::getSetting("batching.{$txgroup['type']}.notice", $txgroup['sdd_creditor_id']);
     $new_collection_date = date('YmdHis', strtotime("$latest_submission_date + $notice_period days"));
     CRM_Sepa_Logic_Batching::deferCollectionDate($new_collection_date, $txgroup['sdd_creditor_id']);
     $new_latest_submission_date = date('YmdHis', strtotime("$latest_submission_date"));
diff --git a/CRM/Sepa/Logic/Batching.php b/CRM/Sepa/Logic/Batching.php
index 14cd89ee..f2bbf30f 100644
--- a/CRM/Sepa/Logic/Batching.php
+++ b/CRM/Sepa/Logic/Batching.php
@@ -460,11 +460,11 @@ protected static function syncGroups($calculated_groups, $existing_groups, $mode
         // this group does not yet exist -> create
 
         // find unused reference
-        $reference = "TXG-${creditor_id}-${mode}-${collection_date}";
+        $reference = "TXG-{$creditor_id}-{$mode}-{$collection_date}";
         $counter = 0;
         while (self::referenceExists($reference)) {
           $counter += 1;
-          $reference = "TXG-${creditor_id}-${mode}-${collection_date}--".$counter;
+          $reference = "TXG-{$creditor_id}-{$mode}-{$collection_date}--".$counter;
         }
 
         // call the hook
diff --git a/CRM/Sepa/Page/CreateMandate.php b/CRM/Sepa/Page/CreateMandate.php
index cbd959f9..71ea6ad9 100644
--- a/CRM/Sepa/Page/CreateMandate.php
+++ b/CRM/Sepa/Page/CreateMandate.php
@@ -34,7 +34,7 @@ function run() {
     CRM_Utils_System::setTitle(ts('Create SEPA Mandate', array('domain' => 'org.project60.sepa')));
     if (isset($_REQUEST['mandate_type'])) {
       $contact_id = $_REQUEST['contact_id'];
-      $this->assign("back_url", CRM_Utils_System::url('civicrm/contact/view', "reset=1&cid=${contact_id}&selectedChild=contribute"));
+      $this->assign("back_url", CRM_Utils_System::url('civicrm/contact/view', "reset=1&cid={$contact_id}&selectedChild=contribute"));
 
       $errors = $this->validateParameters($_REQUEST['mandate_type']);
       if (count($errors) > 0) {
diff --git a/CRM/Utils/SepaCustomisationHooks.php b/CRM/Utils/SepaCustomisationHooks.php
index f13fd201..5b202da6 100644
--- a/CRM/Utils/SepaCustomisationHooks.php
+++ b/CRM/Utils/SepaCustomisationHooks.php
@@ -48,7 +48,7 @@ static function create_mandate(&$mandate_parameters) {
   /**
    * This hook is called when a new transaction group is generated
    *
-   * The default implementation is "TXG-${creditor_id}-${mode}-${collection_date}"
+   * The default implementation is "TXG-{$creditor_id}-{$mode}-{$collection_date}"
    *
    * Be aware the the reference has to be unique. You will have to use suffixes
    *  if your preferred reference is already in use.