diff --git a/jedi/evaluate/context/function.py b/jedi/evaluate/context/function.py
index 816c68c7..c48ab5fc 100644
--- a/jedi/evaluate/context/function.py
+++ b/jedi/evaluate/context/function.py
@@ -140,7 +140,7 @@ class FunctionContext(use_metaclass(CachedMetaClass, FunctionMixin, TreeContext)
         return function
 
     def py__class__(self):
-        c, = contexts_from_qualified_names(self.evaluator, 'types', 'FunctionType')
+        c, = contexts_from_qualified_names(self.evaluator, u'types', u'FunctionType')
         return c
 
     def get_default_param_context(self):
diff --git a/jedi/evaluate/context/instance.py b/jedi/evaluate/context/instance.py
index de3c2b51..0621e4c5 100644
--- a/jedi/evaluate/context/instance.py
+++ b/jedi/evaluate/context/instance.py
@@ -370,7 +370,7 @@ class BoundMethod(FunctionMixin, ContextWrapper):
         self.instance = instance
 
     def py__class__(self):
-        c, = contexts_from_qualified_names(self.evaluator, 'types', 'MethodType')
+        c, = contexts_from_qualified_names(self.evaluator, u'types', u'MethodType')
         return c
 
     def _get_arguments(self, arguments):
diff --git a/jedi/evaluate/context/module.py b/jedi/evaluate/context/module.py
index 6a472e6d..8c44d5bb 100644
--- a/jedi/evaluate/context/module.py
+++ b/jedi/evaluate/context/module.py
@@ -105,7 +105,7 @@ class ModuleMixin(SubModuleDictMixin):
             yield star_filter
 
     def py__class__(self):
-        c, = contexts_from_qualified_names(self.evaluator, 'types', 'ModuleType')
+        c, = contexts_from_qualified_names(self.evaluator, u'types', u'ModuleType')
         return c
 
     def is_module(self):