diff --git a/src/Resources/config/doctrine/MollieCustomer.orm.xml b/src/Resources/config/doctrine/MollieCustomer.orm.xml
index 4af09368..c6dfce70 100644
--- a/src/Resources/config/doctrine/MollieCustomer.orm.xml
+++ b/src/Resources/config/doctrine/MollieCustomer.orm.xml
@@ -11,6 +11,6 @@
         </id>
         <field name="profileId" column="profile_id" type="string" unique="true"/>
         <field name="email" column="email" type="string" unique="true"/>
-        <field name="isCreditCardSaved" column="is_credit_card_saved" type="string"/>
+        <field name="isCreditCardSaved" column="is_credit_card_saved" type="string" nullable="true"/>
     </mapped-superclass>
 </doctrine-mapping>