diff --git a/jedi/evaluate/filters.py b/jedi/evaluate/filters.py
index 63553a46..8ecc1c7a 100644
--- a/jedi/evaluate/filters.py
+++ b/jedi/evaluate/filters.py
@@ -72,12 +72,14 @@ class ParamName(ContextName):
 
     def _get_param(self):
         params = self.parent_context.get_params()
-        return params[self.tree_name.parent.position_nr]
+        param_node = search_ancestor(self.tree_name, 'param')
+        return params[param_node.position_nr]
 
 
 class AnonymousInstanceParamName(ParamName):
     def infer(self):
-        if self.tree_name.parent.position_nr == 0:
+        param_node = search_ancestor(self.tree_name, 'param')
+        if param_node.position_nr == 0:
             # This is a speed optimization, to return the self param (because
             # it's known). This only affects anonymous instances.
             return set([self.parent_context.instance])
diff --git a/jedi/evaluate/instance.py b/jedi/evaluate/instance.py
index 31ed6d32..1a255460 100644
--- a/jedi/evaluate/instance.py
+++ b/jedi/evaluate/instance.py
@@ -324,6 +324,31 @@ class SelfNameFilter(InstanceClassFilter):
                     yield name
 
 
+class ParamArguments(object):
+    """
+    TODO This seems like a strange class, clean up?
+    """
+    class LazyParamContext(object):
+        def __init__(self, fucking_param):
+            self._param = fucking_param
+
+        def infer(self):
+            return self._param.infer()
+
+    def __init__(self, class_context, funcdef):
+        self._class_context = class_context
+        self._funcdef = funcdef
+
+    def unpack(self, func=None):
+        params = search_params(
+            self._class_context.evaluator,
+            self._class_context,
+            self._funcdef
+        )
+        for p in params:
+            yield None, self.LazyParamContext(p)
+
+
 class InstanceVarArgs(object):
     def __init__(self, instance, funcdef, var_args):
         self._instance = instance
@@ -334,11 +359,8 @@ class InstanceVarArgs(object):
     def _get_var_args(self):
         if self._var_args is None:
             # TODO this parent_context might be wrong. test?!
-            return search_params(
-                self._instance.evaluator,
-                self._instance.class_context,
-                self._funcdef
-            )
+            return ParamArguments(self._instance.class_context, self._funcdef)
+
         return self._var_args
 
     def unpack(self, func=None):
diff --git a/jedi/evaluate/param.py b/jedi/evaluate/param.py
index 89d1c726..efa1a036 100644
--- a/jedi/evaluate/param.py
+++ b/jedi/evaluate/param.py
@@ -8,6 +8,7 @@ from jedi.evaluate import iterable
 from jedi.evaluate import analysis
 from jedi.evaluate import context
 from jedi.evaluate import docstrings
+from jedi.evaluate import pep0484
 
 
 def try_iter_content(types, depth=0):
@@ -184,7 +185,7 @@ class ExecutedParam(object):
         self.string_name = self._original_param.name.value
 
     def infer(self):
-        pep0484_hints = set()#pep0484.follow_param(evaluator, param)
+        pep0484_hints = pep0484.follow_param(self._root_context, self._original_param)
         doc_params = docstrings.follow_param(self._root_context, self._original_param)
         if pep0484_hints or doc_params:
             return list(set(pep0484_hints) | set(doc_params))
diff --git a/jedi/evaluate/pep0484.py b/jedi/evaluate/pep0484.py
index 43744cde..99d2bd97 100644
--- a/jedi/evaluate/pep0484.py
+++ b/jedi/evaluate/pep0484.py
@@ -77,8 +77,8 @@ def _fix_forward_reference(context, node):
         return node
 
 
-@memoize_default(None, evaluator_is_first_arg=True)
-def follow_param(evaluator, param):
+@memoize_default()
+def follow_param(context, param):
     annotation = param.annotation()
     return _evaluate_for_annotation(context, annotation)
 
@@ -96,7 +96,7 @@ def py__annotations__(funcdef):
     return dct
 
 
-@memoize_default(None, evaluator_is_first_arg=True)
+@memoize_default()
 def find_return_types(context, func):
     annotation = py__annotations__(func).get("return", None)
     return _evaluate_for_annotation(context, annotation)
diff --git a/jedi/evaluate/representation.py b/jedi/evaluate/representation.py
index 8ea6fec5..9ae40c0b 100644
--- a/jedi/evaluate/representation.py
+++ b/jedi/evaluate/representation.py
@@ -644,7 +644,7 @@ class FunctionExecutionContext(Executed):
         else:
             returns = funcdef.returns
             types = set(docstrings.find_return_types(self.get_root_context(), funcdef))
-            types |= set(pep0484.find_return_types(self.evaluator, funcdef))
+            types |= set(pep0484.find_return_types(self.get_root_context(), funcdef))
 
         for r in returns:
             check = flow_analysis.reachability_check(self, funcdef, r)