diff --git a/tools/config.sh b/tools/config.sh
index 5dec59bef..d33b07f62 100644
--- a/tools/config.sh
+++ b/tools/config.sh
@@ -38,7 +38,7 @@ export SCODOC_DB_TEST="SCODOC_TEST"
 
 
 # psql command: if various versions installed, force the one we want:
-if [ "${debian_version}" = "10" ]
+if [ "${debian_version}" = "11" ]
 then
  PSQL=/usr/lib/postgresql/11/bin/psql
  export POSTGRES_SERVICE="postgresql@11-main.service"
diff --git a/tools/install_debian11.sh b/tools/install_debian11.sh
index 6dab18edf..55d2342fa 100755
--- a/tools/install_debian11.sh
+++ b/tools/install_debian11.sh
@@ -21,7 +21,7 @@ check_uid_root "$0"
 cd "$SCODOC_DIR" || die "can't cd $SCODOC_DIR"
 
 # ------------ Safety checks
-if [ "${debian_version}" != "10" ]
+if [ "${debian_version}" != "11" ]
 then
    echo "Version du systeme Linux Debian incompatible"
    exit 1
@@ -70,7 +70,7 @@ python3 -m venv venv || die "can't create Python 3 virtualenv"
 # ------------ INSTALL DES PAQUETS PYTHON (3.7)
 # ScoDoc8 uses pip in our env
 source venv/bin/activate
-pip install --upgrade pip
+# pip install --upgrade pip => bug [Errno 39] Directory not empty: '_internal'
 pip install wheel
 pip install -r requirements-3.7.txt
 
diff --git a/tools/utils.sh b/tools/utils.sh
index 53965b493..b79027f2e 100644
--- a/tools/utils.sh
+++ b/tools/utils.sh
@@ -61,8 +61,7 @@ init_postgres_user() { # run as root
 
 # --- Ensure Unix user "scodoc" exists
 check_create_scodoc_user() {
-    id -u "${SCODOC_USER}" &> /dev/null
-    if [ "$?" != 0 ]
+    if ! id -u "${SCODOC_USER}" &> /dev/null
     then
         echo "Creating unix user ${SCODOC_USER}"
         adduser --no-create-home --shell /bin/bash --gecos "ScoDoc service" "${SCODOC_USER}" || die "failed to create user"