diff --git a/preinstall b/preinstall
index 39ee118..a5df09d 100755
--- a/preinstall
+++ b/preinstall
@@ -6,16 +6,17 @@ export LANG=C.UTF-8
 export LANGUAGE=C
 export LC_ALL=C.UTF-8
 
-apt-get --yes --no-install-recommends install jq
-
-mac="$(ip -j a show dev eth0 | jq -r .[].address | head -n1)"
-if [ -z "${mac}" ]; then
-  mac="$(ip -j a show dev end0 | jq -r .[].address | head -n1)"
-fi
-if [ -n "${mac}" ]; then
-  echo "mac - ${mac}"
-  echo -e "[Match]\nMACAddress=${mac}\n[Link]\nName=eth0" > /etc/systemd/network/10-persistent-eth0.link
-  echo "Please reboot the system now."
+if grep -rq raspberrypi.org /etc/apt/*; then
+  apt-get --yes --no-install-recommends install jq
+  mac="$(ip -j a show dev eth0 | jq -r .[].address | head -n1)"
+  if [ -z "${mac}" ]; then
+    mac="$(ip -j a show dev end0 | jq -r .[].address | head -n1)"
+  fi
+  if [ -n "${mac}" ]; then
+    echo "mac - ${mac}"
+    echo -e "[Match]\nMACAddress=${mac}\n[Link]\nName=eth0" > /etc/systemd/network/10-persistent-eth0.link
+    echo "Please reboot the system now."
+  fi
 fi
 
 exit 0