diff --git a/preface.asciidoc b/preface.asciidoc
index 85d5f2e..b4c9183 100644
--- a/preface.asciidoc
+++ b/preface.asciidoc
@@ -184,6 +184,7 @@ Following is a list of notable GitHub contributors, including their GitHub ID in
 * Craig Dodd (cdodd)
 * dallyshalla
 * Darius Kramer (dkrmr)
+* David Huie (DavidHuie)
 * Diego Viola (diegoviola)
 * Dirk Jäckel (biafra23)
 * Dimitris Tsapakidis (dimitris-t)
@@ -220,6 +221,7 @@ Following is a list of notable GitHub contributors, including their GitHub ID in
 * Jonathan Cross (jonathancross)
 * Jorgeminator
 * Kai Bakker (kaibakker)
+* Lucas Betschart (lclc)
 * Magomed Aliev (30mb1)
 * Mai-Hsuan Chia (mhchia)
 * marcofalke
@@ -237,6 +239,7 @@ Following is a list of notable GitHub contributors, including their GitHub ID in
 * Richard Kiss (richardkiss)
 * Ruben Alexander (hizzvizz)
 * Sam Ritchie (sritchie)
+* Sebastian Falbesoner (theStack)
 * Sergej Kotliar (ziggamon)
 * Seiichi Uchida (topecongiro)
 * Simon de la Rouviere (simondlr)
@@ -249,4 +252,5 @@ Following is a list of notable GitHub contributors, including their GitHub ID in
 * wintercooled
 * wjx
 * Wojciech Langiewicz (wlk)
+* Yancy Ribbens (yancyribbens)
 * yurigeorgiev4((("", startref="acknowledge0")))