diff --git a/autosklearn/pipeline/components/base.py b/autosklearn/pipeline/components/base.py
index 7b496842b2..04d7259a81 100644
--- a/autosklearn/pipeline/components/base.py
+++ b/autosklearn/pipeline/components/base.py
@@ -43,7 +43,7 @@ def __init__(self, base_class):
         self.components = OrderedDict()
 
     def add_component(self, obj):
-        if inspect.isclass(obj) and self.base_class in obj.__bases__:
+        if inspect.isclass(obj) and isinstance(obj, self.base_class):
             name = obj.__name__
             classifier = obj
         else: