diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index caf7e9d..861d08a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: debian:stretch
+image: debian:stretch-slim
 
 stages:
   - build
diff --git a/install-and-chroot.sh b/install-and-chroot.sh
index 2c276d2..415c536 100755
--- a/install-and-chroot.sh
+++ b/install-and-chroot.sh
@@ -23,6 +23,7 @@ fi
 if ! test -d "$DIR"; then
   sudo bash ./$SCRIPT -d $DIR -m http://ftp.halifax.rwth-aachen.de/alpine \
     -p abuild \
+    -p bash \
     -p build-base \
     -p git \
     -p lua-argparse \
@@ -37,7 +38,7 @@ fi
 sudo sed -e 's/#rc_sys=""/rc_sys="prefix"/g' -i "$DIR/etc/rc.conf"
 
 # Launch chroot
-bash $DIR/enter-chroot ./build || exit 1
+sh $DIR/enter-chroot ./build || exit 1
 
 # Insert pkg++ configuration in chroot
 sudo mkdir -p "$DIR/opt/pkgxx/dev" && \