diff --git a/jedi/api/classes.py b/jedi/api/classes.py
index aa4bc320..a1d3ce8a 100644
--- a/jedi/api/classes.py
+++ b/jedi/api/classes.py
@@ -345,12 +345,20 @@ class BaseDefinition(object):
                 params = followed.params
         elif followed.isinstance(er.compiled.CompiledObject):
             params = followed.params
-        else:
+        elif isinstance(followed, er.Class):
             try:
                 sub = followed.get_subscope_by_name('__init__')
                 params = sub.params[1:]  # ignore self
             except KeyError:
                 return []
+        elif isinstance(followed, er.Instance):
+            try:
+                sub = followed.get_subscope_by_name('__call__')
+                params = sub.params[1:]  # ignore self
+            except KeyError:
+                return []
+        else:
+            return []
         return [_Param(self._evaluator, p.name) for p in params]
 
     def parent(self):
diff --git a/jedi/api/helpers.py b/jedi/api/helpers.py
index adb9564e..8102cc7f 100644
--- a/jedi/api/helpers.py
+++ b/jedi/api/helpers.py
@@ -3,12 +3,11 @@ Helpers for the API
 """
 import re
 from collections import namedtuple
-from textwrap import dedent
 
 from jedi._compatibility import u
 from jedi.evaluate.helpers import call_of_leaf
 from jedi import parser
-from jedi.parser import tokenize, token
+from jedi.parser import tokenize
 from jedi.cache import time_cache
 from jedi import common
 
@@ -279,7 +278,7 @@ def get_call_signature_details(module, position):
             # makes it feel strange to have a call signature.
             return None
 
-        for n in node.children:
+        for n in node.children[::-1]:
             if n.start_pos < position and n.type == 'error_node':
                 result = _get_call_signature_details_from_error_node(n, position)
                 if result is not None:
diff --git a/test/completion/named_param.py b/test/completion/named_param.py
index 317c8455..b420df16 100644
--- a/test/completion/named_param.py
+++ b/test/completion/named_param.py
@@ -33,3 +33,16 @@ multiple(foo, bar
 my_lambda = lambda lambda_param: lambda_param + 1
 #? 22 ['lambda_param']
 my_lambda(lambda_param)
+
+# __call__
+class Test(object):
+    def __init__(self, hello_other):
+        pass
+
+    def __call__(self, hello):
+        pass
+
+#? 12 ['hello']
+Test()(hello=)
+#? 11 []
+Test()(self=)