diff --git a/woocommerce-advanced-ordernumbers.php b/woocommerce-advanced-ordernumbers.php
index 14219bd34ebf2dd98e593d774298d225572d3152..73e866b449313c07916f439e131b5a90be3c0fef 100644
--- a/woocommerce-advanced-ordernumbers.php
+++ b/woocommerce-advanced-ordernumbers.php
@@ -110,7 +110,9 @@ if ( in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', g
 				add_option ('ordernumber_step',      '1');
 
 				// register actions
-				add_filter( 'woocommerce_get_sections_checkout', array($this, 'add_admin_section'),1);
+				add_filter( 'woocommerce_get_sections_checkout', array($this, 'add_admin_section'));
+				// Add the ordernumber post meta to the search in the backend
+				add_filter( 'woocommerce_shop_order_search_fields', array($this, 'order_search_fields'));
 				// The checkout page assumes all subpages are payment gateways, so we have to override this:
 				add_action( 'woocommerce_settings_checkout', array( $this, 'output' ) );
 				add_action( 'woocommerce_settings_save_checkout', array( $this, 'save' ) );
@@ -146,6 +148,15 @@ if ( in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', g
 					WC_Admin_Settings::save_fields( $settings );
 				}
 			}
+			
+			/** 
+			 * Hook to add the order numer post meta field to the searchable field 
+			 * (so the admin can search for the order number in the backend)
+			 */
+			public function order_search_fields($fields) {
+				$fields[] = $this->ordernumber_meta;
+				return $fields;
+			}
 
 			/**
 			 * Counter handling (simple loading/storing counters), storing them as options