diff --git a/avocado/core/tree.py b/avocado/core/tree.py
index 918c53ff93c05275bfd048a14862f7a687b3314e..c70bbac16bf3dc87c78ffa4abc1348cf8cca2a4d 100644
--- a/avocado/core/tree.py
+++ b/avocado/core/tree.py
@@ -57,6 +57,9 @@ class FilterSet(set):
         return super(FilterSet, self).update([self.__normalize(item)
                                               for item in items])
 
+    def __str__(self):
+        return 'FilterSet([%s])' % ', '.join(["'%s'" % i for i in self])
+
 
 class TreeEnvironment(dict):