diff --git a/api.py b/api.py
index d4fd5050..68c13ddc 100644
--- a/api.py
+++ b/api.py
@@ -119,7 +119,7 @@ class CallDef(object):
 
     @property
     def params(self):
-        if isinstance(self.executable, evaluate.Function):
+        if self.executable.isinstance(evaluate.Function):
             return self.executable.params
         else:
             try:
@@ -128,6 +128,10 @@ class CallDef(object):
             except KeyError:
                 return []
 
+    @property
+    def bracket_start(self):
+        return self.call.name.end_pos
+
     def __repr__(self):
         return '<%s: %s index %s>' % (self.__class__.__name__, self.executable,
                                     self.index)
diff --git a/plugin/jedi.vim b/plugin/jedi.vim
index 6f1aef9b..b44fa0bf 100644
--- a/plugin/jedi.vim
+++ b/plugin/jedi.vim
@@ -511,16 +511,16 @@ def _goto(is_definition=False, is_related_name=False, no_output=False):
 
 
 def show_func_def(call_def, completion_lines=0):
-    row, column = vim.current.window.cursor
     vim.eval('jedi#clear_func_def()')
 
     if call_def is None:
         return
 
+    row, column = call_def.bracket_start
     if column < 2 or row == 0:
         return  # edge cases, just ignore
 
-    row_to_replace = row - 1
+    row_to_replace = row - 1  # TODO check if completion menu is above or below
     line = vim.eval("getline(%s)" % row_to_replace)
 
     insert_column = column - 2 # because it has stuff at the beginning