diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index b9ec5fc5..311af8c4 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -50,20 +50,20 @@ if expr "$1" : "apache" 1>/dev/null; then
 fi
 
 if expr "$1" : "apache" 1>/dev/null || [ "$1" = "php-fpm" ] || [ "${NEXTCLOUD_UPDATE:-0}" -eq 1 ]; then
-    if [ -n "${REDIS_HOST+x}" ]; then
+    if [[ -v REDIS_HOST ]]; then
 
         echo "Configuring Redis as session handler"
         {
             echo 'session.save_handler = redis'
             # check if redis host is an unix socket path
             if [ "$(echo "$REDIS_HOST" | cut -c1-1)" = "/" ]; then
-              if [ -n "${REDIS_HOST_PASSWORD+x}" ]; then
+              if [[ -v REDIS_HOST_PASSWORD ]]; then
                 echo "session.save_path = \"unix://${REDIS_HOST}?auth=${REDIS_HOST_PASSWORD}\""
               else
                 echo "session.save_path = \"unix://${REDIS_HOST}\""
               fi
             # check if redis password has been set
-            elif [ -n "${REDIS_HOST_PASSWORD+x}" ]; then
+            elif [[ -v REDIS_HOST_PASSWORD ]]; then
                 echo "session.save_path = \"tcp://${REDIS_HOST}:${REDIS_HOST_PORT:=6379}?auth=${REDIS_HOST_PASSWORD}\""
             else
                 echo "session.save_path = \"tcp://${REDIS_HOST}:${REDIS_HOST_PORT:=6379}\""
@@ -112,10 +112,10 @@ if expr "$1" : "apache" 1>/dev/null || [ "$1" = "php-fpm" ] || [ "${NEXTCLOUD_UP
             file_env NEXTCLOUD_ADMIN_PASSWORD
             file_env NEXTCLOUD_ADMIN_USER
 
-            if [ -n "${NEXTCLOUD_ADMIN_USER+x}" ] && [ -n "${NEXTCLOUD_ADMIN_PASSWORD+x}" ]; then
+            if [[ -v NEXTCLOUD_ADMIN_USER ]] && [[ -v NEXTCLOUD_ADMIN_PASSWORD ]]; then
                 # shellcheck disable=SC2016
                 install_options='-n --admin-user "$NEXTCLOUD_ADMIN_USER" --admin-pass "$NEXTCLOUD_ADMIN_PASSWORD"'
-                if [ -n "${NEXTCLOUD_DATA_DIR+x}" ]; then
+                if [[ -v NEXTCLOUD_DATA_DIR ]]; then
                     # shellcheck disable=SC2016
                     install_options=$install_options' --data-dir "$NEXTCLOUD_DATA_DIR"'
                 fi
@@ -128,17 +128,17 @@ if expr "$1" : "apache" 1>/dev/null || [ "$1" = "php-fpm" ] || [ "${NEXTCLOUD_UP
                 file_env POSTGRES_USER
 
                 install=false
-                if [ -n "${SQLITE_DATABASE+x}" ]; then
+                if[[ -v SQLITE_DATABASE ]]; then
                     echo "Installing with SQLite database"
                     # shellcheck disable=SC2016
                     install_options=$install_options' --database-name "$SQLITE_DATABASE"'
                     install=true
-                elif [ -n "${MYSQL_DATABASE+x}" ] && [ -n "${MYSQL_USER+x}" ] && [ -n "${MYSQL_PASSWORD+x}" ] && [ -n "${MYSQL_HOST+x}" ]; then
+                elif [[ -v MYSQL_DATABASE ]] && [[ -v MYSQL_USER ]] && [[ -v MYSQL_PASSWORD ]] && [[ -v MYSQL_HOST ]]; then
                     echo "Installing with MySQL database"
                     # shellcheck disable=SC2016
                     install_options=$install_options' --database mysql --database-name "$MYSQL_DATABASE" --database-user "$MYSQL_USER" --database-pass "$MYSQL_PASSWORD" --database-host "$MYSQL_HOST"'
                     install=true
-                elif [ -n "${POSTGRES_DB+x}" ] && [ -n "${POSTGRES_USER+x}" ] && [ -n "${POSTGRES_PASSWORD+x}" ] && [ -n "${POSTGRES_HOST+x}" ]; then
+                elif [[ -v POSTGRES_DB ]] && [[ -v POSTGRES_USER ]] && [[ -v POSTGRES_PASSWORD ]] && [[ -v POSTGRES_HOST ]]; then
                     echo "Installing with PostgreSQL database"
                     # shellcheck disable=SC2016
                     install_options=$install_options' --database pgsql --database-name "$POSTGRES_DB" --database-user "$POSTGRES_USER" --database-pass "$POSTGRES_PASSWORD" --database-host "$POSTGRES_HOST"'
@@ -159,7 +159,7 @@ if expr "$1" : "apache" 1>/dev/null || [ "$1" = "php-fpm" ] || [ "${NEXTCLOUD_UP
                         echo "installing of nextcloud failed!"
                         exit 1
                     fi
-                    if [ -n "${NEXTCLOUD_TRUSTED_DOMAINS+x}" ]; then
+                    if [[ -v NEXTCLOUD_TRUSTED_DOMAINS ]]; then
                         echo "setting trusted domains…"
                         NC_TRUSTED_DOMAIN_IDX=1
                         for DOMAIN in $NEXTCLOUD_TRUSTED_DOMAINS ; do