diff --git a/IPython/core/component.py b/IPython/core/component.py
index f7a4d4c..83406db 100644
--- a/IPython/core/component.py
+++ b/IPython/core/component.py
@@ -59,34 +59,30 @@ class MetaComponentTracker(type):
                 c.__instance_refs[c.__numcreated] = instance
         return instance
 
-    def get_instances(cls, name=None, klass=None, root=None):
+    def get_instances(cls, name=None, root=None):
         """Get all instances of cls and its subclasses.
 
         Parameters
         ----------
         name : str
             Limit to components with this name.
-        klass : class
-            Limit to components having isinstance(component, klass)
         root : Component or subclass
             Limit to components having this root.
         """
         instances = cls.__instance_refs.values()
         if name is not None:
             instances = [i for i in instances if i.name == name]
-        if klass is not None:
-            instances = [i for i in instances if isinstance(i, klass)]
         if root is not None:
             instances = [i for i in instances if i.root == root]
         return instances
 
-    def get_instances_by_condition(cls, call, name=None, klass=None, root=None):
+    def get_instances_by_condition(cls, call, name=None, root=None):
         """Get all instances of cls, i such that call(i)==True.
 
-        This also takes the ``name``, ``klass`` and ``root`` arguments of
+        This also takes the ``name`` and ``root`` arguments of
         :meth:`get_instance`
         """
-        return [i for i in cls.get_instances(name,klass,root) if call(i)]
+        return [i for i in cls.get_instances(name, root) if call(i)]
 
 
 class ComponentNameGenerator(object):
diff --git a/IPython/core/tests/test_component.py b/IPython/core/tests/test_component.py
index bc21616..5db9ed9 100644
--- a/IPython/core/tests/test_component.py
+++ b/IPython/core/tests/test_component.py
@@ -52,7 +52,7 @@ class TestComponentMeta(TestCase):
         c2 = MyOtherComponent(c1)
         c3 = MyOtherComponent(c2)
         self.assertEquals(MyComponent.get_instances(), [c1, c2, c3])
-        self.assertEquals(MyComponent.get_instances(klass=MyOtherComponent), [c2, c3])
+        self.assertEquals(MyOtherComponent.get_instances(), [c2, c3])
 
     def test_get_instances_root(self):
         class MyComponent(Component):