diff --git a/searx/engines/xpath.py b/searx/engines/xpath.py
index d420e250..1507176e 100644
--- a/searx/engines/xpath.py
+++ b/searx/engines/xpath.py
@@ -7,7 +7,6 @@ url_xpath = None
 content_xpath = None
 title_xpath = None
 thumbnail_xpath = False
-categories = []
 paging = False
 suggestion_xpath = ''
 results_xpath = ''
@@ -39,7 +38,7 @@ def request(query, params):
 def response(resp):
     results = []
     dom = html.fromstring(resp.text)
-    is_onion = True if 'onions' in categories else False
+    is_onion = True if 'onions' in categories else False  # pylint: disable=undefined-variable
 
     if results_xpath:
         for result in eval_xpath_list(dom, results_xpath):
diff --git a/searx/results.py b/searx/results.py
index 5bf4e6b9..fb7e816e 100644
--- a/searx/results.py
+++ b/searx/results.py
@@ -309,10 +309,11 @@ class ResultContainer:
 
         for res in results:
             # FIXME : handle more than one category per engine
-            res['category'] = engines[res['engine']].categories[0]
+            engine = engines[res['engine']]
+            res['category'] = engine.categories[0] if len(engine.categories) > 0 else ''
 
             # FIXME : handle more than one category per engine
-            category = engines[res['engine']].categories[0]\
+            category = res['category']\
                 + ':' + res.get('template', '')\
                 + ':' + ('img_src' if 'img_src' in res or 'thumbnail' in res else '')