diff --git a/third_party/2and3/yaml/__init__.pyi b/third_party/2and3/yaml/__init__.pyi
index 693981194ea1..4e23a6b13371 100644
--- a/third_party/2and3/yaml/__init__.pyi
+++ b/third_party/2and3/yaml/__init__.pyi
@@ -22,31 +22,46 @@ def safe_load_all(stream: Union[str, IO[str]]) -> Iterator[Any]: ...
 def emit(events, stream=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=...): ...
 
 @overload
-def serialize_all(nodes, stream: None=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> AnyStr: ...
+def serialize_all(nodes, stream: None=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
+@overload
+def serialize_all(nodes, stream: None=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
 @overload
 def serialize_all(nodes, stream: IO[str], Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
-def serialize(node, stream=..., Dumper=..., **kwds): ...
+@overload
+def serialize(node, stream: None=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
+@overload
+def serialize(node, stream: None=..., Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
+@overload
+def serialize(node, stream: IO[str], Dumper=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
 @overload
-def dump_all(documents: Sequence[Any], stream: None=..., Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> AnyStr: ...
+def dump_all(documents: Sequence[Any], stream: None=..., Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
+@overload
+def dump_all(documents: Sequence[Any], stream: None=..., Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
 @overload
 def dump_all(documents: Sequence[Any], stream: IO[str], Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
 @overload
-def dump(data: Any, stream: None=..., Dumper=..., **kwds) -> AnyStr: ...
+def dump(data: Any, stream: None=..., Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
+@overload
+def dump(data: Any, stream: None=..., Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
 @overload
-def dump(data: Any, stream: IO[str], Dumper=..., **kwds) -> None: ...
+def dump(data: Any, stream: IO[str], Dumper=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
 @overload
-def safe_dump_all(documents: Sequence[Any], stream: None=..., **kwds) -> AnyStr: ...
+def save_dump_all(documents: Sequence[Any], stream: None=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
 @overload
-def safe_dump_all(documents: Sequence[Any], stream: IO[str], **kwds) -> None: ...
+def save_dump_all(documents: Sequence[Any], stream: None=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
+@overload
+def save_dump_all(documents: Sequence[Any], stream: IO[str], default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
 @overload
-def safe_dump(data: Any, stream: None=..., **kwds) -> AnyStr: ...
+def save_dump(data: Any, stream: None=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: None=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> str: ...
+@overload
+def save_dump(data: Any, stream: None=..., default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding: str=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> bytes: ...
 @overload
-def safe_dump(data: Any, stream: IO[str], **kwds) -> None: ...
+def save_dump(data: Any, stream: IO[str], default_style=..., default_flow_style=..., canonical=..., indent=..., width=..., allow_unicode=..., line_break=..., encoding=..., explicit_start=..., explicit_end=..., version=..., tags=...) -> None: ...
 
 def add_implicit_resolver(tag, regexp, first=..., Loader=..., Dumper=...): ...
 def add_path_resolver(tag, path, kind=..., Loader=..., Dumper=...): ...