More bytes vs. strings documentation.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 0fd4094..14ad8f9 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -694,6 +694,8 @@
 .. function:: getcwd()
 
    Return a string representing the current working directory.
+   May raise UnicodeDecodeError if the current directory path fails
+   to decode in the file system encoding.
    Availability: Unix, Windows.