diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 6f15d48..6d4a9e2 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -56,7 +56,9 @@
 # Insert a '/' unless the first part is empty or already ends in '/'.
 
 def join(a, *p):
-    """Join two or more pathname components, inserting '/' as needed"""
+    """Join two or more pathname components, inserting '/' as needed.
+    If any component is an absolute path, all previous path components
+    will be discarded."""
     path = a
     for b in p:
         if b.startswith('/'):