diff --git a/sphinx/locale/__init__.py b/sphinx/locale/__init__.py
index b3857de2e..44c821937 100644
--- a/sphinx/locale/__init__.py
+++ b/sphinx/locale/__init__.py
@@ -48,7 +48,7 @@ class _TranslationProxy(UserString):
         return object.__new__(cls)
 
     def __getnewargs__(self):
-        # type: () -> Tuple
+        # type: () -> Tuple[str]
         return (self._func,) + self._args  # type: ignore
 
     def __init__(self, func, *args):
diff --git a/sphinx/writers/manpage.py b/sphinx/writers/manpage.py
index ececac185..b6b434e2d 100644
--- a/sphinx/writers/manpage.py
+++ b/sphinx/writers/manpage.py
@@ -75,7 +75,7 @@ class NestedInlineTransform:
                     if matcher(subnode):
                         node.parent.insert(pos + 1, subnode)
                     else:
-                        newnode = node.__class__('', subnode, **node.attributes)
+                        newnode = node.__class__('', '', subnode, **node.attributes)
                         node.parent.insert(pos + 1, newnode)
 
 
diff --git a/sphinx/writers/texinfo.py b/sphinx/writers/texinfo.py
index b26c1055f..2b6cf7e2d 100644
--- a/sphinx/writers/texinfo.py
+++ b/sphinx/writers/texinfo.py
@@ -95,11 +95,12 @@ def find_subsections(section):
     # type: (nodes.Element) -> List[nodes.section]
     """Return a list of subsections for the given ``section``."""
     result = []
-    for child in section.children:
+    for child in section:
         if isinstance(child, nodes.section):
             result.append(child)
             continue
-        result.extend(find_subsections(child))
+        elif isinstance(child, nodes.Element):
+            result.extend(find_subsections(child))
     return result