diff --git a/jedi/api/helpers.py b/jedi/api/helpers.py
index aa272310..c7abf2e0 100644
--- a/jedi/api/helpers.py
+++ b/jedi/api/helpers.py
@@ -6,7 +6,7 @@ from collections import namedtuple
 
 from jedi import common
 from jedi.evaluate import imports
-from jedi.evaluate.helpers import deep_ast_copy
+from jedi.evaluate.helpers import deep_ast_copy, call_of_name
 from jedi import parser
 from jedi.parser import tokenize, token
 
@@ -181,9 +181,7 @@ def evaluate_goto_definition(evaluator, leaf):
     if parent.type == 'atom':
         node = leaf.parent
     elif parent.type == 'trailer':
-        index = parent.parent.children.index(parent)
-        node = deep_ast_copy(parent.parent)
-        node.children = node.children[:index + 1]
+        node = call_of_name(leaf)
 
     if node is None:
         return []
@@ -225,7 +223,7 @@ def _get_call_signature_details_from_error_node(node, position):
             # until the parentheses is enough.
             children = node.children[index:]
             name = element.get_previous_leaf()
-            if name.type == 'name':
+            if name.type == 'name' or name.parent.type == 'trailer':
                 return CallSignatureDetails(
                     element,
                     *_get_index_and_key(children, position)
diff --git a/jedi/evaluate/helpers.py b/jedi/evaluate/helpers.py
index 8995adb1..5d1ccf39 100644
--- a/jedi/evaluate/helpers.py
+++ b/jedi/evaluate/helpers.py
@@ -82,7 +82,7 @@ def call_of_name(name, cut_own_trailer=False):
     #      ignore it, It's not what we want anyway. Or document it better?
     """
     trailer = name.parent
-    if trailer.type != 'trailer' or trailer.children[0] != '.':
+    if trailer.type != 'trailer':
         return name
 
     assert  not cut_own_trailer  # TODO remove
diff --git a/test/test_api/test_call_signatures.py b/test/test_api/test_call_signatures.py
index fb140c20..81d3c026 100644
--- a/test/test_api/test_call_signatures.py
+++ b/test/test_api/test_call_signatures.py
@@ -356,3 +356,16 @@ def test_bracket_start():
         return signatures[0].bracket_start
 
     assert bracket_start('str(') == (1, 3)
+
+
+def test_different_caller():
+    """
+    It's possible to not use names, but another function result or an array
+    index and then get the call signature of it.
+    """
+
+    assert_signature('[str][0](', 'str', 0)
+    assert_signature('[str][0]()', 'str', 0, column=len('[str][0]('))
+
+    assert_signature('(str)(', 'str', 0)
+    assert_signature('(str)()', 'str', 0, column=len('(str)('))