diff --git a/.gitlab-ci/build-toolbox-image.sh b/.gitlab-ci/build-toolbox-image.sh
index da9e1f852..9c0fb5e79 100755
--- a/.gitlab-ci/build-toolbox-image.sh
+++ b/.gitlab-ci/build-toolbox-image.sh
@@ -57,7 +57,10 @@ build_container() {
   local update_mutter=$(mktemp)
   cat > $update_mutter <<-EOF
 	#!/bin/sh
-	/usr/libexec/install-meson-project.sh https://gitlab.gnome.org/GNOME/mutter.git $MUTTER_BRANCH
+	TOOLBOX=\$(. /run/.containerenv; echo \$name)
+	/usr/libexec/install-meson-project.sh \\
+	  --destdir=/ --destdir=/var/lib/extensions/\$TOOLBOX \\
+	  https://gitlab.gnome.org/GNOME/mutter.git $MUTTER_BRANCH
 	EOF
   buildah copy --chmod 755 $build_cntr $update_mutter /usr/bin/update-mutter