diff --git a/GCP-Debian-11.sh b/GCP-Debian-11.sh
index 1bf4be1..bc7a0c9 100644
--- a/GCP-Debian-11.sh
+++ b/GCP-Debian-11.sh
@@ -78,6 +78,10 @@ sudo sysctl -p
 # Rebuild initramfs
 sudo update-initramfs -u
 
+# Update GRUB config
+echo 'GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=isolation_force efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off"' | sudo tee -a /etc/grub.d/40_custom
+sudo update-grub
+
 # Security limit
 echo '* hard core 0' | tee -a /etc/security/limits.conf
 
diff --git a/Kali-Linux.sh b/Kali-Linux.sh
index 3561b46..6a2f03e 100644
--- a/Kali-Linux.sh
+++ b/Kali-Linux.sh
@@ -45,6 +45,13 @@ sudo chmod 644 /etc/sysctl.d/30_security-misc_kexec-disable.conf
 sudo sed -i 's/kernel.yama.ptrace_scope=2/kernel.yama.ptrace_scope=3/g' /etc/sysctl.d/990-security-misc.conf
 sudo sysctl -p
 
+# Rebuild initramfs
+sudo update-initramfs -u
+
+# Update GRUB config
+echo 'GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=isolation_force efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off"' | sudo tee -a /etc/grub.d/40_custom
+sudo update-grub
+
 # Installing tuned first here because virt-what is 1 of its dependencies anyways
 sudo apt install tuned -y
 virt_type=$(virt-what)
diff --git a/RHEL-Server-9.sh b/RHEL-Server-9.sh
index d70814f..05a2ba6 100644
--- a/RHEL-Server-9.sh
+++ b/RHEL-Server-9.sh
@@ -67,9 +67,9 @@ sudo sed -i 's/net.ipv4.icmp_echo_ignore_all=1/net.ipv4.icmp_echo_ignore_all=0/g
 sudo sed -i 's/net.ipv6.icmp.echo_ignore_all=1/net.ipv6.icmp.echo_ignore_all=0/g' /etc/sysctl.d/990-security-misc.conf
 unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/usr/lib/sysctl.d/30_silent-kernel-printk.conf | sudo tee /etc/sysctl.d/30_silent-kernel-printk.conf
 unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/usr/lib/sysctl.d/30_security-misc_kexec-disable.conf | sudo tee /etc/sysctl.d/30_security-misc_kexec-disable.conf
-sudo grubby --update-kernel=ALL --args='spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=on efi=disable_early_pci_dma iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off'
 sudo dracut -f
 sudo sysctl -p
+sudo grubby --update-kernel=ALL --args='spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=on efi=disable_early_pci_dma iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off'
 
 # Systemd hardening
 
diff --git a/Ubuntu-22.04-Server.sh b/Ubuntu-22.04-Server.sh
index 9693536..a480c3f 100644
--- a/Ubuntu-22.04-Server.sh
+++ b/Ubuntu-22.04-Server.sh
@@ -79,6 +79,12 @@ sudo sysctl -p
 # Rebuild initramfs
 sudo update-initramfs -u
 
+# Update GRUB config
+if [ ! -d /boot/efi/EFI/ZBM ]; then
+  echo 'GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=isolation_force efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off"' | sudo tee -a /etc/grub.d/40_custom
+  sudo update-grub
+fi
+
 # Disable telemetry
 sudo systemctl stop apport.service
 sudo systemctl disable apport.service
diff --git a/Ubuntu-23.10-Desktop.sh b/Ubuntu-23.10-Desktop.sh
index ebf78f9..03cfb56 100644
--- a/Ubuntu-23.10-Desktop.sh
+++ b/Ubuntu-23.10-Desktop.sh
@@ -84,6 +84,10 @@ sudo sysctl -p
 # Rebuild initramfs
 sudo update-initramfs -u
 
+# Update GRUB config
+echo 'GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on spec_store_bypass_disable=on l1tf=full,force mds=full,nosmt tsx=off tsx_async_abort=full,nosmt kvm.nx_huge_pages=force nosmt=force l1d_flush=on mmio_stale_data=full,nosmt random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=isolation_force efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on extra_latent_entropy debugfs=off"' | sudo tee -a /etc/grub.d/40_custom
+sudo update-grub
+
 # Systemd Hardening
 sudo mkdir -p /etc/systemd/system/NetworkManager.service.d
 unpriv curl https://gitlab.com/divested/brace/-/raw/master/brace/usr/lib/systemd/system/NetworkManager.service.d/99-brace.conf | sudo tee /etc/systemd/system/NetworkManager.service.d/99-brace.conf