diff --git a/build.rs b/build.rs
index 1bd20216c6..f4e1502f50 100644
--- a/build.rs
+++ b/build.rs
@@ -308,6 +308,7 @@ pub struct Settings {"#
             .to_string(),
     ];
 
+    println!("cargo:rerun-if-changed=settings.toml");
     let settings_toml = fs::read_to_string("settings.toml").expect("Failed to read settings.toml");
     let settings: toml::Table =
         toml::de::from_str(&settings_toml).expect("Failed to parse settings.toml");
diff --git a/schema/mise.json b/schema/mise.json
index 2c316dfcdf..ec5445289a 100644
--- a/schema/mise.json
+++ b/schema/mise.json
@@ -919,7 +919,8 @@
             "package_manager": {
               "default": "npm",
               "description": "Package manager to use for installing npm packages.",
-              "type": "string"
+              "type": "string",
+              "enum": ["npm", "bun", "pnpm"]
             }
           }
         },
diff --git a/settings.toml b/settings.toml
index e648319b8b..b5b245a4a7 100644
--- a/settings.toml
+++ b/settings.toml
@@ -1030,7 +1030,9 @@ Can be one of:
 - `bun`
 - `pnpm`
 """
+enum = ["npm", "bun", "pnpm"]
 env = "MISE_NPM_PACKAGE_MANAGER"
+rust_type = "NpmPackageManager"
 type = "String"
 
 [offline]
diff --git a/src/backend/npm.rs b/src/backend/npm.rs
index 6af1e01c97..2dab5eea10 100644
--- a/src/backend/npm.rs
+++ b/src/backend/npm.rs
@@ -5,6 +5,7 @@ use crate::backend::backend_type::BackendType;
 use crate::cache::{CacheManager, CacheManagerBuilder};
 use crate::cli::args::BackendArg;
 use crate::cmd::CmdLineRunner;
+use crate::config::settings::NpmPackageManager;
 use crate::config::{Config, Settings};
 use crate::install_context::InstallContext;
 use crate::timeout;
@@ -39,22 +40,22 @@ impl Backend for NPMBackend {
         // package manager for installation. We avoid listing all package managers to
         // prevent incorrect dependency edges.
         let settings = Settings::get();
-        let package_manager = settings.npm.package_manager.as_str();
+        let package_manager = settings.npm.package_manager;
         let tool_name = self.tool_name();
 
         // Avoid circular dependency when installing npm itself
         // But we still need the configured package manager for installation
         if tool_name == "npm" {
             return match package_manager {
-                "bun" => Ok(vec!["node", "bun"]),
-                "pnpm" => Ok(vec!["node", "pnpm"]),
-                _ => Ok(vec!["node"]),
+                NpmPackageManager::Bun => Ok(vec!["node", "bun"]),
+                NpmPackageManager::Pnpm => Ok(vec!["node", "pnpm"]),
+                NpmPackageManager::Npm => Ok(vec!["node"]),
             };
         }
 
         // Avoid circular dependency when installing the configured package manager
         // e.g., npm:bun with bun configured, or npm:pnpm with pnpm configured
-        if tool_name == package_manager {
+        if tool_name == package_manager.to_string() {
             // Still need npm for version queries
             return Ok(vec!["node", "npm"]);
         }
@@ -62,10 +63,9 @@ impl Backend for NPMBackend {
         // For regular packages: need npm (for version queries) + configured package manager
         let mut deps = vec!["node", "npm"];
         match package_manager {
-            "bun" => deps.push("bun"),
-            "pnpm" => deps.push("pnpm"),
-            // npm is already in deps
-            _ => {}
+            NpmPackageManager::Bun => deps.push("bun"),
+            NpmPackageManager::Pnpm => deps.push("pnpm"),
+            NpmPackageManager::Npm => {} // npm is already in deps
         }
         Ok(deps)
     }
@@ -149,8 +149,8 @@ impl Backend for NPMBackend {
 
     async fn install_version_(&self, ctx: &InstallContext, tv: ToolVersion) -> Result<ToolVersion> {
         self.check_install_deps(&ctx.config).await;
-        match Settings::get().npm.package_manager.as_str() {
-            "bun" => {
+        match Settings::get().npm.package_manager {
+            NpmPackageManager::Bun => {
                 CmdLineRunner::new("bun")
                     .arg("install")
                     .arg(format!("{}@{}", self.tool_name(), tv.version))
@@ -174,7 +174,7 @@ impl Backend for NPMBackend {
                     .current_dir(tv.install_path())
                     .execute()?;
             }
-            "pnpm" => {
+            NpmPackageManager::Pnpm => {
                 let bin_dir = tv.install_path().join("bin");
                 crate::file::create_dir_all(&bin_dir)?;
                 CmdLineRunner::new("pnpm")
@@ -228,7 +228,7 @@ impl Backend for NPMBackend {
         _config: &Arc<Config>,
         tv: &crate::toolset::ToolVersion,
     ) -> eyre::Result<Vec<std::path::PathBuf>> {
-        if Settings::get().npm.package_manager == "npm" {
+        if Settings::get().npm.package_manager == NpmPackageManager::Npm {
             Ok(vec![tv.install_path()])
         } else {
             Ok(vec![tv.install_path().join("bin")])
@@ -264,8 +264,8 @@ impl NPMBackend {
 
     /// Check dependencies for package installation (npm or bun based on settings)
     async fn check_install_deps(&self, config: &Arc<Config>) {
-        match Settings::get().npm.package_manager.as_str() {
-            "bun" => {
+        match Settings::get().npm.package_manager {
+            NpmPackageManager::Bun => {
                 self.warn_if_dependency_missing(
                     config,
                     "bun",
@@ -276,7 +276,7 @@ impl NPMBackend {
                 )
                 .await
             }
-            "pnpm" => {
+            NpmPackageManager::Pnpm => {
                 self.warn_if_dependency_missing(
                     config,
                     "pnpm",
diff --git a/src/config/settings.rs b/src/config/settings.rs
index 2612b4db0a..88e8894737 100644
--- a/src/config/settings.rs
+++ b/src/config/settings.rs
@@ -73,6 +73,27 @@ pub enum SettingsStatusMissingTools {
     Always,
 }
 
+#[derive(
+    Debug,
+    Clone,
+    Copy,
+    Serialize,
+    Deserialize,
+    Default,
+    strum::EnumString,
+    strum::Display,
+    PartialEq,
+    Eq,
+)]
+#[serde(rename_all = "snake_case")]
+#[strum(serialize_all = "snake_case")]
+pub enum NpmPackageManager {
+    #[default]
+    Npm,
+    Bun,
+    Pnpm,
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum PythonUvVenvAuto {
     #[default]
@@ -359,7 +380,7 @@ impl Settings {
             self.python.venv_auto_create = python_venv_auto_create;
         }
         if self.npm.bun {
-            self.npm.package_manager = "bun".to_string();
+            self.npm.package_manager = NpmPackageManager::Bun;
         }
     }