diff --git a/includes/wc-order-functions.php b/includes/wc-order-functions.php
index f00534164fd..2a0cb9d5f8b 100644
--- a/includes/wc-order-functions.php
+++ b/includes/wc-order-functions.php
@@ -704,7 +704,7 @@ function wc_get_payment_gateway_by_order( $order ) {
 		$order    = wc_get_order( $order_id );
 	}
 
-	return isset( $payment_gateways[ $order->get_payment_method() ] ) ? $payment_gateways[ $order->get_payment_method() ] : false;
+	return is_a( $order, 'WC_Order' ) && isset( $payment_gateways[ $order->get_payment_method() ] ) ? $payment_gateways[ $order->get_payment_method() ] : false;
 }
 
 /**