diff --git a/scripts/debian/schroot-maintenance.sh b/scripts/debian/schroot-maintenance.sh
index 460b173..afad4d1 100755
--- a/scripts/debian/schroot-maintenance.sh
+++ b/scripts/debian/schroot-maintenance.sh
@@ -1,92 +1,93 @@
 #!/bin/bash
 
 set -eux
 
 error () {
   echo "Error: $@" >&2
   exit 1
 }
 
 debian_mirror=http://deb.debian.org/debian/
 
 chroot_basename="${distribution:=unstable}-${architecture:=amd64}-sbuild"
 chroot="source:${chroot_basename}"
 chroot_path="/srv/softwareheritage/sbuild/$distribution-$architecture"
+chroot_overlay_path="/srv/softwareheritage/sbuild/overlay"
 
 if ! schroot -i -c $chroot >/dev/null; then
   echo "Configuring chroot $chroot"
   if [ $distribution = 'sid' ]; then
     aliases=(unstable experimental)
   else
     aliases=("${distribution}-backports")
   fi
 
   chroot_aliases=("$distribution-swh-$architecture")
   for alias in $aliases; do
     chroot_aliases+=("$alias-$architecture" "$alias-swh-$architecture")
   done
 
   sbuild_aliases=()
   for alias in "${chroot_aliases[@]}"; do
       sbuild_aliases+=("${alias}-sbuild")
   done
 
   body="$(cat << EOF
 type=directory
 directory=$chroot_path
 groups=root,sbuild
 root-groups=root,sbuild
 source-groups=root,sbuild
 source-root-groups=root,sbuild
 union-type=overlay
-union-overlay-directory=/var/run
+union-overlay-directory=$chroot_overlay_path
 EOF
           [ $architecture = i386 ] && "echo personality=linux32"
           echo
           )"
 
   (
     IFS=,
     echo "[$distribution-$architecture]"
     echo "aliases=${chroot_aliases[*]}"
     echo "$body"
     echo
     echo "[$distribution-$architecture-sbuild]"
     echo "profile=sbuild"
     echo "aliases=${sbuild_aliases[*]}"
     echo "$body"
   ) | sudo tee /etc/schroot/chroot.d/$chroot_basename >/dev/null
 fi
 
 LOCKDIR="/var/lock/sbuild-package"
 if ! test -d $LOCKDIR; then
   mkdir $LOCKDIR
   chgrp sbuild $LOCKDIR
   chmod 3775 $LOCKDIR
 fi
 umask 002
 
 (
   cd /
   set -x
   flock --exclusive 9
 
   if ! test -d $chroot_path; then
     echo "Creating chroot in $chroot_path"
     sudo debootstrap --variant=buildd --arch=$architecture --include apt-transport-https,ca-certificates $distribution $chroot_path $debian_mirror
   fi
 
   schroot -u root -c $chroot -- bash << EOF
     set -ex
     echo deb $debian_mirror $distribution main > /etc/apt/sources.list
 
     export DEBIAN_FRONTEND=noninteractive
     export UCF_FORCE_CONFFNEW=y UCF_FORCE_CONFFMISS=y
 
     apt-get update
 
     apt-get -y -o DPkg::Options::=--force-confnew dist-upgrade
     apt-get -y autoremove --purge
 EOF
 
 ) 9> $LOCKDIR/$distribution-$architecture.lock