diff --git a/tests/pytype_blacklist.txt b/tests/pytype_blacklist.txt
index 306b62bd0..a48b4ac68 100644
--- a/tests/pytype_blacklist.txt
+++ b/tests/pytype_blacklist.txt
@@ -8,9 +8,6 @@ stdlib/2and3/builtins.pyi
 stdlib/3/typing.pyi
 stdlib/3/collections/__init__.pyi # parse only
 
-# builtins not found
-stdlib/2/os/__init__.pyi # parse only
-
 # pytype doesn't yet support aliases with implicit type parameters
 # (e.g., here, FutureT = Future[T])
 stdlib/3/asyncio/tasks.pyi