diff --git a/layout/_macro/sidebar.ftl b/layout/_macro/sidebar.ftl
index 98958bf..12917a2 100755
--- a/layout/_macro/sidebar.ftl
+++ b/layout/_macro/sidebar.ftl
@@ -88,7 +88,7 @@
                           </#if>
                           <#if options.next_social_email??>
                             <span class="links-of-author-item">
-                                <a href="${options.next_social_email}" target="_blank" title="E-mail">
+                                <a href="${options.next_social_email!}" target="_blank" title="E-mail">
                                 <#if (options.next_social_icon_enable!'true')=='true'>
                                     <i class="fa fa-fw fa-${options.next_social_email_icon!'globe'}"></i>
                                 </#if>