diff --git a/test/_common.py b/test/_common.py
index 00640f5bc..540397cce 100644
--- a/test/_common.py
+++ b/test/_common.py
@@ -257,14 +257,18 @@ class Bag(object):
 def platform_windows():
     import ntpath
     old_path = os.path
-    os.path = ntpath
-    yield
-    os.path = old_path
+    try:
+        os.path = ntpath
+        yield
+    finally:
+        os.path = old_path
 
 @contextmanager
 def platform_posix():
     import posixpath
     old_path = os.path
-    os.path = posixpath
-    yield
-    os.path = old_path
+    try:
+        os.path = posixpath
+        yield
+    finally:
+        os.path = old_path