diff --git a/README.md b/README.md
index c52ad7f..db5c502 100644
--- a/README.md
+++ b/README.md
@@ -13,11 +13,11 @@ It consists of the [kernel image](https://github.com/nix-community/nixos-images/
 Kexec is a mechanism in Linux to load a new kernel from a running Linux to
 replace the current kernel. This is useful for booting the Nixos installer from
 existing Linux distributions, such as server provider that do not offer a NixOS
-option. After running kexec, the NixOS installer exists only in memory. At the time of
-writing, this requires at least 2.5GB of RAM in the system. If not enough RAM
-is available, the initrd cannot be loaded. Because the NixOS runs only in RAM,
-users can reformat all the system's discs to prepare for a new NixOS
-installation.
+option. After running kexec, the NixOS installer exists only in memory. At the
+time of writing, this requires at least 2.5GB of physical RAM (swap does not
+count) in the system. If not enough RAM is available, the initrd cannot be
+loaded. Because the NixOS runs only in RAM, users can reformat all the system's
+discs to prepare for a new NixOS installation.
 
 Currently, there are two variants of kexec: [nixos-kexec-installer](https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/nixos-kexec-installer-x86_64-linux.tar.xz)
 and [kexec bundle](https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/kexec-bundle-x86_64-linux).