diff --git a/jedi/evaluate/context/klass.py b/jedi/evaluate/context/klass.py
index 9c329d5d..acf68b67 100644
--- a/jedi/evaluate/context/klass.py
+++ b/jedi/evaluate/context/klass.py
@@ -233,14 +233,16 @@ class ClassContext(use_metaclass(CachedMetaClass, ClassMixin, FunctionAndClassBa
         if arglist:
             from jedi.evaluate import arguments
             args = arguments.TreeArguments(self.evaluator, self.parent_context, arglist)
-            return [value for key, value in args.unpack() if key is None]
-        else:
-            if self.py__name__() == 'object' \
-                    and self.parent_context == self.evaluator.builtins_module:
-                return []
-            return [LazyKnownContexts(
-                self.evaluator.builtins_module.py__getattribute__('object')
-            )]
+            lst = [value for key, value in args.unpack() if key is None]
+            if lst:
+                return lst
+
+        if self.py__name__() == 'object' \
+                and self.parent_context == self.evaluator.builtins_module:
+            return []
+        return [LazyKnownContexts(
+            self.evaluator.builtins_module.py__getattribute__('object')
+        )]
 
     def py__getitem__(self, index_context_set, contextualized_node):
         from jedi.evaluate.gradual.typing import LazyGenericClass
diff --git a/test/completion/stdlib.py b/test/completion/stdlib.py
index 541e9024..7127efea 100644
--- a/test/completion/stdlib.py
+++ b/test/completion/stdlib.py
@@ -276,3 +276,17 @@ qsplit = shlex.split("foo, ferwerwerw werw werw e")
 for part in qsplit:
     #? str()
     part
+
+# -----------------
+# Unknown metaclass
+# -----------------
+
+# Github issue 1321
+class Meta(object):
+    pass
+
+class Test(metaclass=Meta):
+    def test_function(self):
+        result = super(Test, self).test_function()
+        #? []
+        result.