diff --git a/stdlib/2.7/os/__init__.pyi b/stdlib/2.7/os/__init__.pyi
index c68f48f27..3f9aa0d90 100644
--- a/stdlib/2.7/os/__init__.pyi
+++ b/stdlib/2.7/os/__init__.pyi
@@ -31,8 +31,8 @@ def getppid() -> int: ...
 def getresuid() -> Tuple[int, int, int]: ...
 def getresgid() -> Tuple[int, int, int]: ...
 def getuid() -> int: ...
-def getenv(varname: str, value: str = ...) -> str: ...
-def putenv(varname: str, value: str) -> None: ...
+def getenv(varname: unicode, value: unicode = ...) -> str: ...
+def putenv(varname: unicode, value: unicode) -> None: ...
 def setegid(egid: int) -> None: ...
 def seteuid(euid: int) -> None: ...
 def setgid(gid: int) -> None: ...