diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 1fa72dbb..a2fef332 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -302,12 +302,14 @@ class Evaluator(object):
             if trailer.type == 'arglist':
                 trailer = trailer.parent
             if trailer.type != 'classdef':
-                for i, t in enumerate(trailer.parent.children):
-                    if t == trailer:
-                        to_evaluate = trailer.parent.children[:i]
-                types = self.eval_element(to_evaluate[0])
-                for trailer in to_evaluate[1:]:
-                    types = self.eval_trailer(types, trailer)
+                if trailer.type == 'decorator':
+                    types = self.eval_element(trailer.children[1])
+                else:
+                    i = trailer.parent.children.index(trailer)
+                    to_evaluate = trailer.parent.children[:i]
+                    types = self.eval_element(to_evaluate[0])
+                    for trailer in to_evaluate[1:]:
+                        types = self.eval_trailer(types, trailer)
                 param_names = []
                 for typ in types:
                     try:
diff --git a/jedi/evaluate/representation.py b/jedi/evaluate/representation.py
index 5fcbb186..126c36c6 100644
--- a/jedi/evaluate/representation.py
+++ b/jedi/evaluate/representation.py
@@ -504,7 +504,6 @@ class Function(use_metaclass(CachedMetaClass, Wrapper)):
         if not self.is_decorated:
             for dec in reversed(decorators):
                 debug.dbg('decorator: %s %s', dec, f)
-                dec.children
                 dec_results = self._evaluator.eval_element(dec.children[1])
                 trailer = dec.children[2:-1]
                 if trailer:
diff --git a/test/completion/goto.py b/test/completion/goto.py
index 18cb8502..1098bed1 100644
--- a/test/completion/goto.py
+++ b/test/completion/goto.py
@@ -191,3 +191,14 @@ for key, value in [(1,2)]:
 for i in []:
     #! ['for i in []: i']
     i
+
+# -----------------
+# decorator
+# -----------------
+def dec(dec_param=3):
+    pass
+
+#! 8 ['dec_param=3']
+@dec(dec_param=5)
+def y():
+    pass