diff --git a/classes/class.pmproemail.php b/classes/class.pmproemail.php
index 42ba504d8..94a27837e 100644
--- a/classes/class.pmproemail.php
+++ b/classes/class.pmproemail.php
@@ -1222,8 +1222,8 @@ function sendInvoiceEmail($user = NULL, $order = NULL)
 								'user_login' => $user->user_login,
 								'sitename' => get_option( 'blogname' ),
 								'siteemail' => get_option( 'pmpro_from_email' ),
-								'membership_id' => $membership_level->id,
-								'membership_level_name' => $membership_level->name,
+								'membership_id' => ( ! empty( $membership_level ) ) ? $membership_level->id : '',
+								'membership_level_name' => ( ! empty( $membership_level ) ) ? $membership_level->name : '',
 								'display_name' => $user->display_name,
 								'user_email' => $user->user_email,	
 								'order_id' => $order->code,