diff --git a/src/image_builder.rs b/src/image_builder.rs
index c1688fb..fed146e 100644
--- a/src/image_builder.rs
+++ b/src/image_builder.rs
@@ -26,15 +26,13 @@ use tempfile::tempdir;
 use crate::nixos;
 use crate::shell::*;
 
-const NIX_VERSION: &str = "2.28.3";
-
 const NIX_CONF: &str = formatcp!(
     "experimental-features = nix-command flakes
 extra-nix-path = nixpkgs=github:nixos/nixpkgs/nixos-{}
 build-users-group =
 sandbox = false
 ",
-    nixos::NIXOS_VERSION
+    crate::NIXOS_VERSION
 );
 
 static BASE_SHA256: &str = "/nix/.base.sha256";
@@ -464,8 +462,8 @@ where
     let nix_store = dest.join("store");
     if !nix_store.exists() {
         log::info!("installing Nix in {}", dest.display());
-        let nix_url = nix_installer_url(NIX_VERSION, arch);
-        download_and_install_nix(NIX_VERSION, arch, &nix_url, dest)?;
+        let nix_url = nix_installer_url(crate::NIX_VERSION, arch);
+        download_and_install_nix(crate::NIX_VERSION, arch, &nix_url, dest)?;
     }
 
     let nix_bin = dest.join(".bin");
@@ -473,7 +471,7 @@ where
     fs::create_dir_all(&gcroots)?;
 
     if !symlink_exists(&nix_bin) {
-        let nix_store_path = find_nix(&nix_store, NIX_VERSION)?;
+        let nix_store_path = find_nix(&nix_store, crate::NIX_VERSION)?;
         let nix_path = Path::new("/nix/store").join(nix_store_path);
         symlink(nix_path.join("bin"), nix_bin).unwrap();
         symlink(&nix_path, gcroots.join("nix")).unwrap();
diff --git a/src/lib.rs b/src/lib.rs
index 60c4dd2..e34bfb3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,6 +13,9 @@ mod embedded_image;
 
 mod pid_file;
 
+pub(crate) const NIX_VERSION: &str = "2.28.3";
+pub(crate) const NIXOS_VERSION: &str = "25.05";
+
 pub(crate) const CACHE_HOME: &str = "/nix/.cache";
 pub(crate) const CONFIG_HOME: &str = "/nix/.config";
 
diff --git a/src/nixos.rs b/src/nixos.rs
index ce1e5a3..188b81d 100644
--- a/src/nixos.rs
+++ b/src/nixos.rs
@@ -8,8 +8,6 @@ use std::{
 use anyhow::{bail, Context, Result};
 use regex::Regex;
 
-pub(crate) const NIXOS_VERSION: &str = "25.05";
-
 pub(crate) const ENV_VARS: [(&str, &str); 4] = [
     ("PATH", "/nix/.bin"),
     ("NIX_CONF_DIR", "/nix/etc"),
@@ -78,7 +76,7 @@ pub fn build_flake_from_package_list(
         match &caps[1] {
             "name" => name,
             "description" => description,
-            "version" => NIXOS_VERSION,
+            "version" => crate::NIXOS_VERSION,
             "packages" => &package_list,
             _ => "",
         }