diff --git a/xap/gammastep/SlackBuild b/xap/gammastep/SlackBuild
new file mode 100755
index 00000000..a1f6728a
--- /dev/null
+++ b/xap/gammastep/SlackBuild
@@ -0,0 +1,83 @@
+#!/bin/bash
+
+# variables
+VERSION=${VERSION:-"trunk"}
+BUILD=${BUILD:-1}
+
+TAG=gwh
+TMP=/tmp/$TAG
+CWD=$(pwd)
+
+PRGNAM=$(basename $CWD)
+PKG=$TMP/pkg-$PRGNAM
+OUTPUT=${OUTPUT:-/tmp}
+
+ARCH=${ARCH:-$(uname -m)}
+
+REPOSITORY=${REPOSITORY:-/home/installs/SlackBuilds/repositories/$PRGNAM}
+PREFIX=${PREFIX:-/usr}
+
+# nettoyage préalable
+rm -fr $PKG $TMP/$PRGNAM-$VERSION
+
+mkdir -p $PKG
+
+# mise en place
+cd $TMP
+[ ! -e $REPOSITORY ] && git clone https://gitlab.com/chinstrap/gammastep.git $REPOSITORY
+cd $REPOSITORY
+git pull --all
+
+cp -R $REPOSITORY $TMP/
+cd $TMP/$PRGNAM
+[ "x$VERSION" == "xtrunk" ] && VERSION="git_$(git log -1 --format=%h_%ad --date=format:%Y.%m.%d)" || git checkout $VERSION
+
+./bootstrap
+./configure \
+ --prefix=$PREFIX \
+ --libdir=$PREFIX/lib$(uname -m | grep -o 64) \
+ --mandir=$PREFIX/man \
+ --enable-wayland \
+ --enable-gui
+
+make
+make install DESTDIR=$PKG
+
+# move doc/ to the appropriate location
+mkdir -p $PKG$PREFIX/doc/$PRGNAM
+cp LICENCE* *.md $PKG$PREFIX/doc/$PRGNAM
+
+# correction
+cd $PKG
+chown -R root:root *
+
+find $PKG$PREFIX/man -type f -not -name \*.gz -exec gzip -9 {} \;
+
+# embaumement
+mkdir -p $PKG/install
+
+cat <<EOF > $PKG/install/slack-desc
+# HOW TO EDIT THIS FILE:
+# The "handy ruler" below makes it easier to edit a package description.  Line
+# up the first '|' above the ':' following the base package name, and the '|'
+# on the right side marks the last column you can put a character in.  You must
+# make exactly 11 lines for the formatting to be correct.  It's also
+# customary to leave one space after the ':'.
+
+       |-----handy-ruler------------------------------------------------------|
+$PRGNAM: $PRGNAM (screen color adjuster)
+$PRGNAM:
+$PRGNAM: Adjust the color temperature of your screen according to
+$PRGNAM: your surroundings. This may help your eyes hurt less if you are
+$PRGNAM: working in front of the screen at night.
+$PRGNAM: Run gammastep -h for help on command line options.
+$PRGNAM: A graphical indicator is provided, gammastep-indicator.
+$PRGNAM:
+$PRGNAM:
+$PRGNAM:
+$PRGNAM: https://gitlab.com/chinstrap/gammastep
+EOF
+
+# empaquetage
+rm -f $PKG/{,usr/}lib$(uname -m | grep -o 64)/*.la
+/sbin/makepkg -l y -c n $OUTPUT/$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.txz