diff --git a/setup.py b/setup.py
index 8d40de1a8..dfc80578f 100644
--- a/setup.py
+++ b/setup.py
@@ -44,7 +44,7 @@ extras_require = {
     'lint': [
         'flake8>=3.5.0',
         'isort',
-        'mypy>=0.790',
+        'mypy>=0.800',
         'docutils-stubs',
     ],
     'test': [
diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index 2c96ede32..699ab8189 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -92,7 +92,7 @@ class Stylesheet(str):
     filename = None     # type: str
 
     def __new__(cls, filename: str, *args: str, **attributes: str) -> "Stylesheet":
-        self = str.__new__(cls, filename)  # type: ignore
+        self = str.__new__(cls, filename)
         self.filename = filename
         self.attributes = attributes
         self.attributes.setdefault('rel', 'stylesheet')
@@ -115,7 +115,7 @@ class JavaScript(str):
     filename = None     # type: str
 
     def __new__(cls, filename: str, **attributes: str) -> "JavaScript":
-        self = str.__new__(cls, filename)  # type: ignore
+        self = str.__new__(cls, filename)
         self.filename = filename
         self.attributes = attributes
 
diff --git a/sphinx/util/i18n.py b/sphinx/util/i18n.py
index e149976ef..3c1030d62 100644
--- a/sphinx/util/i18n.py
+++ b/sphinx/util/i18n.py
@@ -34,7 +34,7 @@ if False:
 
 logger = logging.getLogger(__name__)
 
-LocaleFileInfoBase = namedtuple('CatalogInfo', 'base_dir,domain,charset')
+LocaleFileInfoBase = namedtuple('LocaleFileInfoBase', 'base_dir,domain,charset')
 
 
 class CatalogInfo(LocaleFileInfoBase):