QSQLITE driver not loaded

Hello!
We already had a rdk board by phytec with a qt application using a sqlite database (I just had to add sqlite to IMAGE_INSTALL_append), but for some reasons we switched to toradex now. As I could see, sqlite3 is already included in the console-trdx-image, so it should work out of the box (certainly, i had to add the qt libs). So this is, what my IMAGE_INSTALL_append looks like now:

IMAGE_INSTALL_append = " qtbase qtbase-plugins qtbase-fonts qtdeclarative qtdeclarative-plugins qtserialport qtwebsocket"

I also tried adding sqlite (→ the old version 2), but whenever I start our application, I always get the following error:

QSqlDatabase: QSQLITE driver not loaded
QSqlDatabase: available drivers:
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins

However, i can open the database file on the console with sqlite3 dbfile.db, so sqlite seems to be installed properly. I think Qt just cannot find the driver libary, but I don’t know how to fix this.

Systeminfo:

CoM: Toradex Colibri iMX6 Solo 256MB | V1.0A 
SBC: Viola Plus | V1.2A Plus
Image: console-trdx-image
Version: 2.6 / v2015.12 / jethro / 2.0