diff --git a/build/scripts/ffmpeg.sh b/build/scripts/ffmpeg.sh
index e715c7b..04b90fb 100644
--- a/build/scripts/ffmpeg.sh
+++ b/build/scripts/ffmpeg.sh
@@ -8,7 +8,7 @@ export_env SDK_URL https://www.dropbox.com/s/wel0xazy2c45pqe/$SDK_BASENAME.zip
 apt_install_permanent sudo linux-libc-dev
 
 ## Cuda
-echo 'deb http://deb.debian.org/debian $DEBIAN main contrib non-free' >> /etc/apt/sources.list
+echo "deb http://deb.debian.org/debian $DEBIAN main contrib non-free" >> /etc/apt/sources.list
 apt_install_permanent libcuda1 libnvidia-encode1
 
 ## FFmpeg
diff --git a/build/scripts/multimedia.sh b/build/scripts/multimedia.sh
index be35046..65f4628 100644
--- a/build/scripts/multimedia.sh
+++ b/build/scripts/multimedia.sh
@@ -1,4 +1,4 @@
 ## Enable multimedia sources in APT
-echo 'deb http://www.deb-multimedia.org $DEBIAN main non-free' >> /etc/apt/sources.list
-echo 'deb-src http://www.deb-multimedia.org $DEBIAN main non-free' >> /etc/apt/sources.list
+echo "deb http://www.deb-multimedia.org $DEBIAN main non-free" >> /etc/apt/sources.list
+echo "deb-src http://www.deb-multimedia.org $DEBIAN main non-free" >> /etc/apt/sources.list
 apt_install_permanent deb-multimedia-keyring
diff --git a/build/scripts/prepare.sh b/build/scripts/prepare.sh
index 7375ffc..6c39aeb 100644
--- a/build/scripts/prepare.sh
+++ b/build/scripts/prepare.sh
@@ -45,3 +45,6 @@ apt dist-upgrade -y --no-install-recommends
 ## Set timezone
 echo $TIMEZONE > /etc/timezone
 dpkg-reconfigure -f noninteractive tzdata
+
+## Store debian
+export_env DEBIAN $DEBIAN