diff --git a/modules/openstack_project/files/nodepool/scripts/restrict_memory.sh b/modules/openstack_project/files/nodepool/scripts/restrict_memory.sh
index 332e2fcba8..a5fd406aba 100755
--- a/modules/openstack_project/files/nodepool/scripts/restrict_memory.sh
+++ b/modules/openstack_project/files/nodepool/scripts/restrict_memory.sh
@@ -19,8 +19,13 @@
 # cpu resources can be used without the risk of becoming dependent on more
 # memory.
 if [ -f /etc/default/grub ] ; then
-    sudo sed -i -e 's/^GRUB_TIMEOUT=[0-9]\+/GRUB_TIMEOUT=0/' -e 's/#\?GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="mem=8G"/g' /etc/default/grub
-    sudo update-grub
+    sudo sed -i -e 's/^GRUB_TIMEOUT=[0-9]\+/GRUB_TIMEOUT=0/' -e 's/#\?GRUB_CMDLINE_LINUX="/GRUB_CMDLINE_LINUX="mem=8G /g' /etc/default/grub
+    if which update-grub &> /dev/null ; then
+        sudo update-grub
+    else
+        # If update-grub isn't available, use grub2-mkconfig directly
+        sudo grub2-mkconfig -o /boot/grub2/grub.cfg
+    fi
 elif [ -f /boot/grub/grub.conf ] ; then
     sudo sed -i -e 's/^timeout=[0-9]\+/timeout=0/' -e 's/\(^\s\+kernel.*\)/\1 mem=8G/' /boot/grub/grub.conf
 fi