diff --git a/x11/lightdm-gtk-greeter/Makefile b/x11/lightdm-gtk-greeter/Makefile
--- a/x11/lightdm-gtk-greeter/Makefile
+++ b/x11/lightdm-gtk-greeter/Makefile
@@ -2,7 +2,7 @@
 
 PORTNAME=	lightdm-gtk-greeter
 PORTVERSION=	2.0.8
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	x11
 MASTER_SITES=	https://github.com/Xubuntu/${PORTNAME}/releases/download/${PORTNAME}-${PORTVERSION}/
 
@@ -23,6 +23,7 @@
 
 GNU_CONFIGURE=	yes
 INSTALLS_ICONS=	yes
+SUB_FILES=	pkg-deinstall pkg-install
 
 CONFIGURE_ARGS+=--disable-indicator-services-command \
 	--enable-at-spi-command=${LOCALBASE}/libexec/at-spi-bus-launcher
diff --git a/x11/lightdm-gtk-greeter/files/pkg-deinstall.in b/x11/lightdm-gtk-greeter/files/pkg-deinstall.in
new file mode 100644
--- /dev/null
+++ b/x11/lightdm-gtk-greeter/files/pkg-deinstall.in
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+PREFIX=${PKG_PREFIX-/usr/local}
+
+case $2 in
+DEINSTALL)
+	if grep -Fxq "greeter-session=lightdm-gtk-greeter" ${PREFIX}/etc/lightdm/lightdm.conf
+	then
+		echo ":: Removing greeter configuration in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Configure another greeter if you plan to keep using lightdm."
+		/usr/bin/sed -i ".bak" "s/^greeter-session=lightdm-gtk-greeter$/#greeter-session=example-gtk-gnome/g" \
+			${PREFIX}/etc/lightdm/lightdm.conf
+	else
+		echo ":: lightdm-gtk-greeter is not the configured greeter in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Leaving the lightdm greeter configuration unchanged."
+	fi
+	echo ":: $(grep greeter-session= ${PREFIX}/etc/lightdm/lightdm.conf)"
+	;;
+esac
diff --git a/x11/lightdm-gtk-greeter/files/pkg-install.in b/x11/lightdm-gtk-greeter/files/pkg-install.in
new file mode 100644
--- /dev/null
+++ b/x11/lightdm-gtk-greeter/files/pkg-install.in
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+PREFIX=${PKG_PREFIX-/usr/local}
+
+case $2 in
+POST-INSTALL)
+	if grep -Fxq "#greeter-session=example-gtk-gnome" ${PREFIX}/etc/lightdm/lightdm.conf
+	then
+		echo ":: Setting lightdm-gtk-greeter as greeter session in ${PREFIX}/etc/lightdm/lightdm.conf"
+		/usr/bin/sed -i ".bak" "s/^#greeter-session=example-gtk-gnome$/greeter-session=lightdm-gtk-greeter/g" \
+			${PREFIX}/etc/lightdm/lightdm.conf
+	else
+		echo ":: A greeter has already been configured in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Leaving the lightdm greeter configuration unchanged."
+	fi
+	echo ":: $(grep greeter-session= ${PREFIX}/etc/lightdm/lightdm.conf)"
+	;;
+esac
diff --git a/x11/slick-greeter/Makefile b/x11/slick-greeter/Makefile
--- a/x11/slick-greeter/Makefile
+++ b/x11/slick-greeter/Makefile
@@ -3,7 +3,7 @@
 PORTNAME=	slick-greeter
 PORTVERSION=	1.5.3
 CATEGORIES=	x11
-PORTREVISION=	1
+PORTREVISION=	2
 
 MAINTAINER=	ericbsd@FreeBSD.org
 COMMENT=	Slick-looking LightDM greeter
@@ -34,6 +34,7 @@
 		makepot
 bash_OLD_CMD=	/usr/bin/bash
 bash_CMD=	/bin/sh
+SUB_FILES=	pkg-deinstall pkg-install
 
 GLIB_SCHEMAS=	x.dm.slick-greeter.gschema.xml
 
diff --git a/x11/slick-greeter/files/pkg-deinstall.in b/x11/slick-greeter/files/pkg-deinstall.in
new file mode 100644
--- /dev/null
+++ b/x11/slick-greeter/files/pkg-deinstall.in
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+PREFIX=${PKG_PREFIX-/usr/local}
+
+case $2 in
+DEINSTALL)
+	if grep -Fxq "greeter-session=slick-greeter" ${PREFIX}/etc/lightdm/lightdm.conf
+	then
+		echo ":: Removing greeter configuration in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Configure another greeter if you plan to keep using lightdm."
+		/usr/bin/sed -i ".bak" "s/^greeter-session=slick-greeter$/#greeter-session=example-gtk-gnome/g" \
+			${PREFIX}/etc/lightdm/lightdm.conf
+	else
+		echo ":: slick-greeter is not the configured greeter in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Leaving the lightdm greeter configuration unchanged."
+	fi
+	echo ":: $(grep greeter-session= ${PREFIX}/etc/lightdm/lightdm.conf)"
+	;;
+esac
diff --git a/x11/slick-greeter/files/pkg-install.in b/x11/slick-greeter/files/pkg-install.in
new file mode 100644
--- /dev/null
+++ b/x11/slick-greeter/files/pkg-install.in
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+PREFIX=${PKG_PREFIX-/usr/local}
+
+case $2 in
+POST-INSTALL)
+	if grep -Fxq "#greeter-session=example-gtk-gnome" ${PREFIX}/etc/lightdm/lightdm.conf
+	then
+		echo ":: Setting slick-greeter as greeter session in ${PREFIX}/etc/lightdm/lightdm.conf"
+		/usr/bin/sed -i ".bak" "s/^#greeter-session=example-gtk-gnome$/greeter-session=slick-greeter/g" \
+			${PREFIX}/etc/lightdm/lightdm.conf
+	else
+		echo ":: A greeter has already been configured in ${PREFIX}/etc/lightdm/lightdm.conf"
+		echo ":: Leaving the lightdm greeter configuration unchanged."
+	fi
+	echo ":: $(grep greeter-session= ${PREFIX}/etc/lightdm/lightdm.conf)"
+	;;
+esac