diff --git a/htdocs/categories/class/categorie.class.php b/htdocs/categories/class/categorie.class.php
index dad25199566..f860023ed4f 100644
--- a/htdocs/categories/class/categorie.class.php
+++ b/htdocs/categories/class/categorie.class.php
@@ -332,6 +332,7 @@ class Categorie extends CommonObject
 
 		// Check parameters
 		if (empty($id) && empty($label) && empty($ref_ext)) {
+			$this->error = "No category to search for";
 			return -1;
 		}
 		if (!is_null($type) && !is_numeric($type)) {
@@ -389,6 +390,7 @@ class Categorie extends CommonObject
 
 				return 1;
 			} else {
+				$this->error = "No category found";
 				return 0;
 			}
 		} else {