unittest.mock minor doc update
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
index 1b39697..bed698a 100644
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -1359,7 +1359,7 @@
 
 .. function:: patch.stopall
 
-    Stop all active patches.
+    Stop all active patches. Only stops patches started with `start`.
 
 
 TEST_PREFIX