diff --git a/Lib/string.py b/Lib/string.py
index 6faa1f0..9477268 100644
--- a/Lib/string.py
+++ b/Lib/string.py
@@ -513,7 +513,8 @@
 
     Return a copy of string str with all occurrences of substring
     old replaced by new. If the optional argument maxsplit is
-    given, only the first maxsplit occurrences are replaced.
+    given, only the first maxsplit occurrences are replaced. A
+    negative value of maxsplit signifies all occurances.
 
     """
     return s.replace(old, new, maxsplit)