diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 224a93eb..13a40030 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -136,12 +136,12 @@ class Evaluator(object):
 
     def import_module(self, import_names, parent_module_context, sys_path):
         try:
-            return ContextSet(self.module_cache.get(import_names))
+            return self.module_cache.get(import_names)
         except KeyError:
             pass
 
         context_set = self._import_module(import_names, parent_module_context, sys_path)
-        self.module_cache.add(context_set, import_names)
+        self.module_cache.add(import_names, context_set)
         return context_set
 
     @property
diff --git a/jedi/evaluate/context/function.py b/jedi/evaluate/context/function.py
index d9efd75b..370428f3 100644
--- a/jedi/evaluate/context/function.py
+++ b/jedi/evaluate/context/function.py
@@ -103,7 +103,7 @@ class FunctionContext(use_metaclass(CachedMetaClass, AbstractFunction)):
 
         function = create(tree_node)
 
-        if len(overloaded_funcs) > 1:
+        if overloaded_funcs:
             return OverloadedFunctionContext(
                 function,
                 ContextSet.from_iterable(create(f) for f in overloaded_funcs)
@@ -365,6 +365,9 @@ def _find_overload_functions(context, tree_node):
                     return True
         return False
 
+    if tree_node.type == 'lambdef':
+        return
+
     if _is_overload_decorated(tree_node):
         yield tree_node
 
@@ -381,4 +384,5 @@ def _find_overload_functions(context, tree_node):
             if funcdef.type == 'funcdef' and _is_overload_decorated(funcdef):
                 yield funcdef
 
+        # TODO this is probably not good enough? Why are we always breaking?
         break  # By default break
diff --git a/jedi/evaluate/context/typing.py b/jedi/evaluate/context/typing.py
index af205cb7..af8317a6 100644
--- a/jedi/evaluate/context/typing.py
+++ b/jedi/evaluate/context/typing.py
@@ -510,7 +510,7 @@ class _AbstractAnnotatedClass(ClassContext):
 
     @to_list
     def py__bases__(self):
-        for base in super().py__bases__():
+        for base in super(_AbstractAnnotatedClass, self).py__bases__():
             yield LazyAnnotatedBaseClass(self, base)