diff --git a/ChangeLog b/ChangeLog
index 4b16576793..7b253d05cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -19,6 +19,9 @@ Release Date: TBA
 
 * Use ``inference_tip`` for ``typing.TypedDict`` brain.
 
+* Fix inference of attributes defined in a base class that is an inner class
+
+  Closes #904
 
 What's New in astroid 2.5.2?
 ============================
diff --git a/astroid/inference.py b/astroid/inference.py
index 926dabd9be..72281bb00a 100644
--- a/astroid/inference.py
+++ b/astroid/inference.py
@@ -315,6 +315,7 @@ def infer_attribute(self, context=None):
         elif not context:
             context = contextmod.InferenceContext()
 
+        old_boundnode = context.boundnode
         try:
             context.boundnode = owner
             yield from owner.igetattr(self.attrname, context)
@@ -325,7 +326,7 @@ def infer_attribute(self, context=None):
         ):
             pass
         finally:
-            context.boundnode = None
+            context.boundnode = old_boundnode
     return dict(node=self, context=context)
 
 
diff --git a/tests/unittest_inference.py b/tests/unittest_inference.py
index 07765cd540..b35553bd3d 100644
--- a/tests/unittest_inference.py
+++ b/tests/unittest_inference.py
@@ -3890,6 +3890,72 @@ class Clazz(metaclass=_Meta):
         ).inferred()[0]
         assert isinstance(cls, nodes.ClassDef) and cls.name == "Clazz"
 
+    def test_infer_subclass_attr_outer_class(self):
+        node = extract_node(
+            """
+        class Outer:
+            data = 123
+
+        class Test(Outer):
+            pass
+        Test.data
+        """
+        )
+        inferred = next(node.infer())
+        self.assertIsInstance(inferred, nodes.Const)
+        self.assertEqual(inferred.value, 123)
+
+    def test_infer_subclass_attr_inner_class_works_from_classdef(self):
+        node = extract_node(
+            """
+        class Outer:
+            class Inner:
+                data = 123
+
+        class Test(Outer.Inner):
+            pass
+        Test
+        """
+        )
+        cls_def = next(node.infer())
+        self.assertIsInstance(cls_def, nodes.ClassDef)
+        inferred = next(cls_def.igetattr('data'))
+        self.assertIsInstance(inferred, nodes.Const)
+        self.assertEqual(inferred.value, 123)
+
+    def test_infer_subclass_attr_inner_class_works_indirectly(self):
+        node = extract_node(
+            """
+        class Outer:
+            class Inner:
+                data = 123
+        Inner = Outer.Inner
+
+        class Test(Inner):
+            pass
+        Test.data
+        """
+        )
+        inferred = next(node.infer())
+        self.assertIsInstance(inferred, nodes.Const)
+        self.assertEqual(inferred.value, 123)
+
+    def test_infer_subclass_attr_inner_class(self):
+        node = extract_node(
+            """
+        class Outer:
+            class Inner:
+                data = 123
+
+        class Test(Outer.Inner):
+            pass
+        Test.data
+        """
+        )
+        inferred = next(node.infer())
+        self.assertIsInstance(inferred, nodes.Const)
+        self.assertEqual(inferred.value, 123)
+
     def test_delayed_attributes_without_slots(self):
         ast_node = extract_node(
             """