diff --git a/jedi/evaluate/context/instance.py b/jedi/evaluate/context/instance.py
index db94c91a..36da32fc 100644
--- a/jedi/evaluate/context/instance.py
+++ b/jedi/evaluate/context/instance.py
@@ -443,7 +443,7 @@ class SelfAttributeFilter(ClassFilter):
         for name in names:
             trailer = name.parent
             if trailer.type == 'trailer' \
-                    and len(trailer.children) == 2 \
+                    and len(trailer.parent.children) == 2 \
                     and trailer.children[0] == '.':
                 if name.is_definition() and self._access_possible(name):
                     yield name
diff --git a/test/completion/classes.py b/test/completion/classes.py
index 1c192370..4bd2963b 100644
--- a/test/completion/classes.py
+++ b/test/completion/classes.py
@@ -36,6 +36,7 @@ class TestClass(object):
         self2.var_inst = first_param
         self2.second = second_param
         self2.first = first_param
+        self2.first.var_on_argument = 5
         a = 3
 
     def var_func(self):