diff --git a/AUTHORS b/AUTHORS
index de0c9c7..6ec8e46 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -57,6 +57,14 @@
 David Woodhouse has helped out with test and build machines over the course
 of many releases.
 
+Florian Krohm and Christian Borntraeger wrote and maintain the
+S390X/Linux port.  Florian improved and ruggedised the regression test
+system during 2011.
+
+Philippe Waroquiers wrote and maintains the embedded GDB server.  He
+also made a bunch of performance and memory-reduction fixes across
+diverse parts of the system.
+
 Many, many people sent bug reports, patches, and helpful feedback.
 
 Development of Valgrind was supported in part by the Tri-Lab Partners