diff --git a/docs/persistent-identifiers.rst b/docs/persistent-identifiers.rst
index 4021ce7a5fdbef17eb4e5499746ac2397f358996..b6d8c812dd9157f5b208fb241dbdd93febf4e73e 100644
--- a/docs/persistent-identifiers.rst
+++ b/docs/persistent-identifiers.rst
@@ -4,7 +4,7 @@
 SoftWare Heritage persistent IDentifiers (SWHIDs)
 =================================================
 
-**version 1.2**
+**version 1.3, last modified 2020-04-28**
 
 
 Overview