diff --git a/htdocs/categories/class/api_categories.class.php b/htdocs/categories/class/api_categories.class.php
index e10371f87b6..77356ba2a87 100644
--- a/htdocs/categories/class/api_categories.class.php
+++ b/htdocs/categories/class/api_categories.class.php
@@ -267,8 +267,8 @@ class Categories extends DolibarrApi
 			throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
 		}
 
-		if (!$this->category->delete(DolibarrApiAccess::$user)) {
-			throw new RestException(401, 'error when delete category');
+		if ($this->category->delete(DolibarrApiAccess::$user) <= 0) {
+			throw new RestException(500, 'Error when delete category : ' . $this->category->error);
 		}
 
 		return array(
diff --git a/htdocs/societe/class/api_contacts.class.php b/htdocs/societe/class/api_contacts.class.php
index afd6c5807a5..d8839c9a122 100644
--- a/htdocs/societe/class/api_contacts.class.php
+++ b/htdocs/societe/class/api_contacts.class.php
@@ -348,7 +348,7 @@ class Contacts extends DolibarrApi
 	 * Delete contact
 	 *
 	 * @param   int     $id Contact ID
-	 * @return  integer
+	 * @return  array[]
 	 */
 	public function delete($id)
 	{
@@ -364,7 +364,17 @@ class Contacts extends DolibarrApi
 			throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
 		}
 		$this->contact->oldcopy = clone $this->contact;
-		return $this->contact->delete();
+
+		if ($this->contact->delete() <= 0) {
+			throw new RestException(500, 'Error when delete contact ' . $this->contact->error);
+		}
+
+		return array(
+			'success' => array(
+				'code' => 200,
+				'message' => 'Contact deleted'
+			)
+		);
 	}
 
 	/**