diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 234ea3238ef998..158dd9d4d6c1c2 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -2050,7 +2050,8 @@ features:
 
    Create a directory named *path* with numeric mode *mode*.
 
-   If the directory already exists, :exc:`FileExistsError` is raised.
+   If the directory already exists, :exc:`FileExistsError` is raised. If a parent
+   directory in the path does not exist, :exc:`FileNotFoundError` is raised.
 
    .. _mkdir_modebits: