diff --git a/htdocs/product/class/productfournisseurprice.class.php b/htdocs/product/class/productfournisseurprice.class.php
index 6e3b15405d0..93666b0431b 100644
--- a/htdocs/product/class/productfournisseurprice.class.php
+++ b/htdocs/product/class/productfournisseurprice.class.php
@@ -824,7 +824,7 @@ class ProductFournisseurPrice extends CommonObject
 				$dir = dol_buildpath($reldir."core/modules/buypricehistory/");
 
 				// Load file with numbering class (if found)
-				$mybool |= @include_once $dir.$file;
+				$mybool = ((bool) @include_once $dir.$file) || $mybool;
 			}
 
 			if ($mybool === false) {