diff --git a/lib/printf/README b/lib/printf/README
index ac283642d7..46d51cec6a 100644
--- a/lib/printf/README
+++ b/lib/printf/README
@@ -1,6 +1,6 @@
-This is the printf implementation from FreeBSD.  It was imported on 2019-05-12,
-from SVN revision 347514 (but the code hadn't been touched for 2 years before
-that.)
+This is the printf implementation from FreeBSD.  The history of this code is:
+- imported on 2019-05-12, from SVN revision 347514
+- resynced on 2023-09-03, to pick up `%b` implementation
 
 Please don't reindent or otherwise mangle the files to make importing fixes
 easy (not that there are significant changes likely to happen...)