diff --git a/includes/documents/abstract-wcpdf-order-document.php b/includes/documents/abstract-wcpdf-order-document.php
index fff9b18c8..3a5041cd5 100644
--- a/includes/documents/abstract-wcpdf-order-document.php
+++ b/includes/documents/abstract-wcpdf-order-document.php
@@ -326,7 +326,12 @@ public function set_date( $value, $order = null ) {
 
 	public function set_number( $value, $order = null ) {
 		$order = empty( $order ) ? $this->order : $order;
-		if ( empty( $value ) || ( is_array( $value ) && empty( array_filter ( $value ) ) ) ) {
+
+		if ( is_array( $value ) ) {
+			$filtered_value = array_filter( $value );
+		}
+		
+		if ( empty( $value ) || ( is_array( $value ) && empty( $filtered_value ) ) ) {
 			$document_number = null;
 		} elseif ( is_array( $value ) ) {
 			// WCPDF 2.0 number data