diff --git a/Misc/ACKS b/Misc/ACKS
index 820206a..db451d7 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -526,6 +526,7 @@
 Kip Lehman
 Joerg Lehmann
 Robert Lehmann
+Petri Lehtinen
 Luke Kenneth Casson Leighton
 Marc-Andre Lemburg
 John Lenton