diff --git a/README.md b/README.md
index 7318217..d7c90ef 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,9 @@ Set Debian packages server address. Choose a server from the list of Debian worl
 ##### `APT_PROXY`=""
 Set Proxy server address. Using a local Proxy-Cache like `apt-cacher-ng` will speed-up the bootstrapping process because all required Debian packages will only be downloaded from the Debian mirror site once. If `apt-cacher-ng` is running on default `http://127.0.0.1:3142` it is autodetected and you don't need to set this.
 
+##### `KEEP_APT_PROXY`=false
+Keep the APT_PROXY settings used in the bootsrapping process in the generated image.
+
 ##### `APT_INCLUDES`=""
 A comma-separated list of additional packages to be installed by debootstrap during bootstrapping.
 
diff --git a/bootstrap.d/11-apt.sh b/bootstrap.d/11-apt.sh
index 1a05bf3..33b3cc1 100644
--- a/bootstrap.d/11-apt.sh
+++ b/bootstrap.d/11-apt.sh
@@ -16,7 +16,7 @@ install_readonly files/apt/sources.list "${ETC_DIR}/apt/sources.list"
 
 # Use specified APT server and release
 sed -i "s/\/ftp.debian.org\//\/${APT_SERVER}\//" "${ETC_DIR}/apt/sources.list"
-sed -i "s/ jessie/ ${RELEASE}/" "${ETC_DIR}/apt/sources.list"
+sed -i "s/ stretch/ ${RELEASE}/" "${ETC_DIR}/apt/sources.list"
 
 # Upgrade package index and update all installed packages and changed dependencies
 chroot_exec apt-get -qq -y update
diff --git a/files/apt/sources.list b/files/apt/sources.list
index ffc2c9b..07e52dc 100644
--- a/files/apt/sources.list
+++ b/files/apt/sources.list
@@ -1,8 +1,8 @@
-deb http://ftp.debian.org/debian jessie main contrib
-#deb-src http://ftp.debian.org/debian jessie main contrib
+deb http://ftp.debian.org/debian stretch main contrib
+#deb-src http://ftp.debian.org/debian stretch main contrib
 
-deb http://ftp.debian.org/debian/ jessie-updates main contrib
-#deb-src http://ftp.debian.org/debian/ jessie-updates main contrib
+deb http://ftp.debian.org/debian/ stretch-updates main contrib
+#deb-src http://ftp.debian.org/debian/ stretch-updates main contrib
 
-deb http://security.debian.org/ jessie/updates main contrib
-#deb-src http://security.debian.org/ jessie/updates main contrib
+deb http://security.debian.org/ stretch/updates main contrib
+#deb-src http://security.debian.org/ stretch/updates main contrib
diff --git a/rpi23-gen-image.sh b/rpi23-gen-image.sh
index 2ea5bcb..0081612 100755
--- a/rpi23-gen-image.sh
+++ b/rpi23-gen-image.sh
@@ -119,6 +119,7 @@ NET_NTP_2=${NET_NTP_2:=""}
 # APT settings
 APT_PROXY=${APT_PROXY:=""}
 APT_SERVER=${APT_SERVER:="ftp.debian.org"}
+KEEP_APT_PROXY=${KEEP_APT_PROXY:=false}
 
 # Feature settings
 ENABLE_PRINTK=${ENABLE_PRINTK:=false}
@@ -675,13 +676,17 @@ umount -l "${R}/sys"
 rm -rf "${R}/run/*"
 rm -rf "${R}/tmp/*"
 
+# Clean up APT proxy settings
+if [ "$KEEP_APT_PROXY" = false ] ; then
+  rm -f "${ETC_DIR}/apt/apt.conf.d/10proxy"
+fi
+
 # Clean up files
 rm -f "${ETC_DIR}/ssh/ssh_host_*"
 rm -f "${ETC_DIR}/dropbear/dropbear_*"
 rm -f "${ETC_DIR}/apt/sources.list.save"
 rm -f "${ETC_DIR}/resolvconf/resolv.conf.d/original"
 rm -f "${ETC_DIR}/*-"
-rm -f "${ETC_DIR}/apt/apt.conf.d/10proxy"
 rm -f "${ETC_DIR}/resolv.conf"
 rm -f "${R}/root/.bash_history"
 rm -f "${R}/var/lib/urandom/random-seed"