diff --git a/prepare_server.sh b/prepare_server.sh
index 1a19e3c2..1cc18705 100755
--- a/prepare_server.sh
+++ b/prepare_server.sh
@@ -12,7 +12,7 @@ else echo "CI is set to $CI";
 fi
 
 # script should fail when any process returns non zero code
-set -ev
+set -e
 
 # handle arguments
 SKIP_SETUP=false
@@ -37,35 +37,42 @@ done
 
 echo "SKIP_SETUP = ${SKIP_SETUP}"
 
-POSTGRES_DB=${POSTGRES_DB:-vbv_lernwelt}
-POSTGRES_HOST=${POSTGRES_HOST:-localhost}
-POSTGRES_PORT=${POSTGRES_PORT:-5432}
-POSTGRES_USER=${POSTGRES_USER:-postgres}
+# migrate env vars to the built-in postgres variables
+if [ -z ${PGDATABASE+x} ]; then # var is empty
+    PGDATABASE=${POSTGRES_DB:-vbv_lernwelt};
+    POSTGRES_DB=$PGDATABASE
+fi
+if [ -z ${PGHOST+x} ]; then # var is empty
+    PGHOST=${POSTGRES_DB:-localhost};
+fi
+if [ -z ${PGPORT+x} ]; then # var is empty
+    PGPORT=${POSTGRES_PORT:-5432}
+fi
+if [ -z ${PGUSER+x} ]; then # var is empty
+    PGUSER=${POSTGRES_USER:-postgres}
+fi
 DJANGO_PORT=${DJANGO_PORT:-8000}
 
-mypsql() {
-  psql -h "${POSTGRES_HOST}" -p "${POSTGRES_PORT}" -U "${POSTGRES_USER}" "$@"
-}
 
 if [ "$SKIP_SETUP" = false ]; then
     # TODO: in heroku we must do a `pg:resets` to reset the db
     echo "Check postgres connection"
-    mypsql -c "SELECT 1"
-    echo "Drop all connections to $POSTGRES_DB"
-    mypsql -c "SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = '$POSTGRES_DB' AND pid <> pg_backend_pid();" > /dev/null 2>&1
-    echo "Drop database: $POSTGRES_DB"
-    mypsql -c "drop database if exists $POSTGRES_DB;"
-    echo "Create database: $POSTGRES_DB"
-    mypsql -c "create database $POSTGRES_DB;"
+    psql -d postgres -c "SELECT 1" # use default db to connect to
+    echo "Drop all connections to $PGDATABASE"
+    psql -c "SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = '$POSTGRES_DB' AND pid <> pg_backend_pid();" > /dev/null 2>&1
+    echo "Drop database: $PGDATABASE"
+    psql -d postgres -c "drop database if exists $PGDATABASE;" # use default db to drop another database, can't drop the currently connected database
+    echo "Create database: $PGDATABASE"
+    psql -d postgres -c "create database $PGDATABASE;" # use default database, as the set database does not exist currently
 
     echo "initialize database for django"
-    python3 server/manage.py createcachetable --settings="$DJANGO_SETTINGS_MODULE"
-    python3 server/manage.py migrate --settings="$DJANGO_SETTINGS_MODULE"
-    python3 server/manage.py create_default_users --settings="$DJANGO_SETTINGS_MODULE"
-    python3 server/manage.py create_default_courses --settings="$DJANGO_SETTINGS_MODULE"
+    python server/manage.py createcachetable
+    python server/manage.py migrate
+    python server/manage.py create_default_users
+    python server/manage.py create_default_courses
 
     # make django translations
-    (cd server && python3 manage.py compilemessages --settings="$DJANGO_SETTINGS_MODULE")
+    (cd server && python manage.py compilemessages)
 else
     # TODO: can we reset important data without resetting the database?
     echo "Skip database setup"
@@ -73,7 +80,7 @@ else
 fi
 
 if [ "$START_BACKGROUND" = true ]; then
-    cd server && python3 manage.py runserver "${DJANGO_PORT}" --settings="$DJANGO_SETTINGS_MODULE" > /dev/null &
+    cd server && python manage.py runserver "${DJANGO_PORT}" > /dev/null &
 else
-    cd server && python3 manage.py runserver "${DJANGO_PORT}" --settings="$DJANGO_SETTINGS_MODULE"
+    cd server && python manage.py runserver "${DJANGO_PORT}"
 fi
diff --git a/prepare_server_cypress.sh b/prepare_server_cypress.sh
index f8fb3dd3..b08106f5 100755
--- a/prepare_server_cypress.sh
+++ b/prepare_server_cypress.sh
@@ -6,6 +6,6 @@ cd "${0%/*}"
 export IT_APP_ENVIRONMENT=development
 export DJANGO_SETTINGS_MODULE=config.settings.test_cypress
 export DJANGO_PORT=8001
-export POSTGRES_DB=vbv_lernwelt_cypress
+export PGDATABASE=vbv_lernwelt_cypress
 
 ./prepare_server.sh "$@"