diff --git a/jedi/inference/compiled/mixed.py b/jedi/inference/compiled/mixed.py
index 98959fd8..7d76113a 100644
--- a/jedi/inference/compiled/mixed.py
+++ b/jedi/inference/compiled/mixed.py
@@ -71,6 +71,13 @@ class MixedObject(ValueWrapper):
         else:
             return self.compiled_value.get_safe_value(default)
 
+    @property
+    def array_type(self):
+        return self.compiled_value.array_type
+
+    def get_key_values(self):
+        return self.compiled_value.get_key_values()
+
     def py__simple_getitem__(self, index):
         python_object = self.compiled_value.access_handle.access._obj
         if type(python_object) in ALLOWED_GETITEM_TYPES:
diff --git a/test/test_api/test_interpreter.py b/test/test_api/test_interpreter.py
index 1bd06405..ee7617ca 100644
--- a/test/test_api/test_interpreter.py
+++ b/test/test_api/test_interpreter.py
@@ -594,12 +594,18 @@ def test_param_annotation_completion(class_is_findable):
         ('mixed[Non', 9, ['e']),
 
         ('implicit[10', None, ['00']),
+
+        ('inherited["', None, ['blablu"']),
     ]
 )
 def test_dict_completion(code, column, expected):
     strs = {'asdf': 1, u"""foo""": 2, r'fbar': 3}
     mixed = {1: 2, 1.10: 4, None: 6, r'a\sdf': 8, b'foo': 9}
 
+    class Inherited(dict):
+        pass
+    inherited = Inherited(blablu=3)
+
     namespaces = [locals(), {'implicit': {1000: 3}}]
     comps = jedi.Interpreter(code, namespaces).complete(column=column)
     if Ellipsis in expected: