diff --git a/roles/autoinstall-dvbsky-firmware/tasks/main.yml b/roles/autoinstall-dvbsky-firmware/tasks/main.yml
index 64a8b92..12d054a 100644
--- a/roles/autoinstall-dvbsky-firmware/tasks/main.yml
+++ b/roles/autoinstall-dvbsky-firmware/tasks/main.yml
@@ -5,7 +5,7 @@
   block:
     - name: add firmware for DVBSky S952 V3 to variable dvbsky_firmware_files if a card has been detected
       set_fact:
-        dvbsky_firmware_files: dvbsky_firmware_files + [ 'dvb-demod-m88rs6000.fw']
+        dvbsky_firmware_files: "{{dvbsky_firmware_files}} + ['dvb-demod-m88rs6000.fw']"
       when:
         - '"1ade:3038" in pci'
         - ansible_distribution_version >= '15.04'  #driver only included since Kernel 3.19