diff --git a/2.7/_random.pyi b/2.7/_random.pyi
index fca2ccba6..f64595b99 100644
--- a/2.7/_random.pyi
+++ b/2.7/_random.pyi
@@ -3,7 +3,7 @@
 from typing import Optional, Any
 
 class Random(object):
-    def __init__(self, seed: x: object = None) -> None: ...
+    def __init__(self, seed: x, object = None) -> None: ...
     def seed(self, x: object = None) -> None: ...
     def getstate(self) -> tuple: ...
     def setstate(self, state: tuple) -> None: ...
diff --git a/2.7/cStringIO.pyi b/2.7/cStringIO.pyi
index 2b80621de..4afeb83ac 100644
--- a/2.7/cStringIO.pyi
+++ b/2.7/cStringIO.pyi
@@ -26,7 +26,7 @@ class StringIO(IO[str]):
     def writable(self) -> bool: ...
     def writelines(self, lines: Iterable[str]) -> None: ...
     def next(self) -> str: ...
-    def __iter__(self) -> StringI: ...
+    def __iter__(self) -> "InputType": ...
     def __enter__(self) -> Any: ...
     def __exit__(self, exc_type: type, exc_val: Any, exc_tb: Any) -> Any: ...
     # only StringO:
diff --git a/2.7/thread.pyi b/2.7/thread.pyi
index 7688ad921..0dcd5d891 100644
--- a/2.7/thread.pyi
+++ b/2.7/thread.pyi
@@ -23,7 +23,7 @@ class _localdummy(object):
 def start_new(function: Callable[..., Any], args: Any, kwargs: Any = None) -> int: ...
 def start_new_thread(function: Callable[..., Any], args: Any, kwargs: Any = None) -> int: ...
 def interrupt_main() -> None: ...
-def exit() -> None: ...
+def exit() -> None:
     raise SystemExit()
 def exit_thread() -> Any:
     raise SystemExit()
diff --git a/2.7/zlib.pyi b/2.7/zlib.pyi
index d431f3bd5..74eeed33e 100644
--- a/2.7/zlib.pyi
+++ b/2.7/zlib.pyi
@@ -25,12 +25,12 @@ def decompress(data: str, wbits: int = ..., bufsize: int = ...) -> str: ...
 class compressobj:
     def __init__(level: int = ..., method: int = ..., wbits: int = ..., memlevel: int = ...,
                  strategy: int = ...): ...
-    def compress(self, data: str) -> str
-    def copy(self) -> _Compress
-    def flush(self) -> NoneType
+    def compress(self, data: str) -> str: ...
+    def copy(self) -> _Compress: ...
+    def flush(self) -> NoneType: ...
 
 class decompressobj:
     def __init__(wbits: int = ...): ...
-    def copy(self) -> _Compress
-    def decompress(self, data: str) -> str
-    def flush(self) -> NoneType
+    def copy(self) -> _Compress: ...
+    def decompress(self, data: str) -> str: ...
+    def flush(self) -> NoneType: ...