diff --git a/Helper/Data.php b/Helper/Data.php
index 24ed58de..aa39eb2d 100755
--- a/Helper/Data.php
+++ b/Helper/Data.php
@@ -707,6 +707,8 @@ public function getMergeVars(\Magento\Customer\Model\Customer $customer, $storeI
 
                 if (!empty($value)) {
                     $mergeVars[$map['mailchimp']] = $value;
+                } else {
+                    $mergeVars[$map['mailchimp']] = '';
                 }
             }
         }