diff --git a/includes/admin/class-admin.php b/includes/admin/class-admin.php
index 2f6f12d3..05995bad 100644
--- a/includes/admin/class-admin.php
+++ b/includes/admin/class-admin.php
@@ -1532,6 +1532,13 @@ if ( ! class_exists( 'um\admin\Admin' ) ) {
 							$sanitized[ $k ] = absint( $v );
 						}
 						break;
+					case 'empty_absint':
+						if ( is_array( $v ) ) {
+							$sanitized[ $k ] = array_map( 'absint', $v );
+						} else {
+							$sanitized[ $k ] = ( '' !== $v ) ? absint( $v ) : '';
+						}
+						break;
 					case 'key':
 						if ( is_array( $v ) ) {
 							$sanitized[ $k ] = array_map( 'sanitize_key', $v );
diff --git a/includes/admin/core/class-admin-settings.php b/includes/admin/core/class-admin-settings.php
index 6fd47efe..877d464c 100644
--- a/includes/admin/core/class-admin-settings.php
+++ b/includes/admin/core/class-admin-settings.php
@@ -769,7 +769,7 @@ if ( ! class_exists( 'um\admin\core\Admin_Settings' ) ) {
 						'sanitize' => 'bool',
 					),
 					'activation_link_expiry_time'           => array(
-						'sanitize' => 'absint',
+						'sanitize' => 'empty_absint',
 					),
 					'account_tab_password'                  => array(
 						'sanitize' => 'bool',