diff --git a/src/freedombone-image-customise b/src/freedombone-image-customise
index 834be2f7..76555c33 100755
--- a/src/freedombone-image-customise
+++ b/src/freedombone-image-customise
@@ -581,7 +581,7 @@ install_patchwork() {
             exit 8793636
         fi
         chroot "$rootdir" chmod +x /root/npm_install.sh
-        chroot "$rootdir" /root/npm_install.sh $NPM_VERSION
+        chroot "$rootdir" npm_install=$NPM_VERSION /root/npm_install.sh
     fi
 
     git clone https://github.com/ssbc/patchwork $rootdir/etc/patchwork