diff --git a/e2e/cli/test_hook_env b/e2e/cli/test_hook_env
index 8cfdc9229b3..f4b4b3f37d8 100644
--- a/e2e/cli/test_hook_env
+++ b/e2e/cli/test_hook_env
@@ -16,3 +16,13 @@ assert_contains "dummy" "1.0.0"
 export MISE_DUMMY_VERSION=1.1.0
 pushd .. && popd
 assert_contains "dummy" "1.1.0"
+
+ln -s "$ROOT/test/data/plugins/dummy" "$MISE_DATA_DIR/plugins/hyphen-tool"
+mise install hyphen-tool@1.0.0
+mise shell hyphen-tool@1.0.0
+assert "echo $MISE_HYPHEN_TOOL_VERSION" "1.0.0"
+pushd .. && popd
+assert_contains "mise current hyphen-tool" "1.0.0"
+
+mise shell --unset hyphen-tool
+assert "echo ${MISE_HYPHEN_TOOL_VERSION+set}" ""
diff --git a/src/backend/asdf.rs b/src/backend/asdf.rs
index e1e5c0ef491..59d06fb3157 100644
--- a/src/backend/asdf.rs
+++ b/src/backend/asdf.rs
@@ -215,7 +215,7 @@ impl AsdfBackend {
             .with_env("MISE_DOWNLOAD_PATH", download)
             .with_env("MISE_INSTALL_PATH", install)
             .with_env("MISE_INSTALL_TYPE", install_type)
-            .with_env("MISE_INSTALL_VERSION", install_version);
+            .with_env(env::MISE_INSTALL_VERSION_ENV_VAR, install_version);
         Ok(sm)
     }
 }
diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index 4f52463ac1f..2120ec901ae 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -2382,7 +2382,7 @@ pub trait Backend: Debug + Send + Sync {
             .env(&*env::PATH_KEY, path_env.join())
             .env("MISE_TOOL_INSTALL_PATH", tv.install_path())
             .env("MISE_TOOL_NAME", tv.ba().short.clone())
-            .env("MISE_TOOL_VERSION", tv.version.clone())
+            .env(env::MISE_TOOL_VERSION_ENV_VAR, tv.version.clone())
             .with_pr(ctx.pr.as_ref())
             .cmd_body_args(shell_args, &rendered_script)
             .envs(env_vars);
diff --git a/src/cli/shell.rs b/src/cli/shell.rs
index f3321ee249d..5825a435e6e 100644
--- a/src/cli/shell.rs
+++ b/src/cli/shell.rs
@@ -1,13 +1,12 @@
 use color_eyre::eyre::{Result, bail, eyre};
 use console::style;
-use heck::ToShoutySnakeCase;
 use indoc::formatdoc;
 
 use crate::cli::args::ToolArg;
 use crate::config::Config;
 use crate::env;
 use crate::shell::get_shell;
-use crate::toolset::{InstallOptions, ToolSource, ToolsetBuilder};
+use crate::toolset::{InstallOptions, ToolSource, ToolsetBuilder, tool_env_var_name};
 
 /// Sets a tool version for the current session.
 ///
@@ -48,10 +47,7 @@ impl Shell {
 
         if self.unset {
             for ta in &self.tool {
-                let op = shell.unset_env(&format!(
-                    "MISE_{}_VERSION",
-                    ta.ba.short.to_shouty_snake_case()
-                ));
+                let op = shell.unset_env(&tool_env_var_name(&ta.ba.short));
                 print!("{op}");
             }
             return Ok(());
@@ -82,7 +78,7 @@ impl Shell {
         for (p, tv) in ts.list_current_installed_versions(&config) {
             let source = &ts.versions.get(p.ba().as_ref()).unwrap().source;
             if matches!(source, ToolSource::Argument) {
-                let k = format!("MISE_{}_VERSION", p.id().to_shouty_snake_case());
+                let k = tool_env_var_name(p.id());
                 let op = shell.set_env(&k, &tv.version);
                 print!("{op}");
             }
diff --git a/src/env.rs b/src/env.rs
index ab2db128683..cc18978cedc 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -22,6 +22,10 @@ use std::{path::PathBuf, sync::atomic::AtomicBool};
 
 pub static ARGS: RwLock<Vec<String>> = RwLock::new(vec![]);
 pub static TOOL_ARGS: RwLock<Vec<ToolArg>> = RwLock::new(vec![]);
+pub const MISE_INSTALL_VERSION_ENV_VAR: &str = "MISE_INSTALL_VERSION";
+pub const MISE_TOOL_VERSION_ENV_VAR: &str = "MISE_TOOL_VERSION";
+pub const NON_TOOL_VERSION_ENV_VARS: &[&str] =
+    &[MISE_INSTALL_VERSION_ENV_VAR, MISE_TOOL_VERSION_ENV_VAR];
 #[cfg(unix)]
 pub static SHELL: Lazy<String> = Lazy::new(|| var("SHELL").unwrap_or_else(|_| "sh".into()));
 #[cfg(windows)]
diff --git a/src/toolset/builder.rs b/src/toolset/builder.rs
index c1b1ee3790d..4e8c61e8c30 100644
--- a/src/toolset/builder.rs
+++ b/src/toolset/builder.rs
@@ -7,7 +7,7 @@ use crate::cli::args::{BackendArg, ToolArg};
 use crate::config::{Config, ConfigMap};
 use crate::env_diff::EnvMap;
 use crate::errors::Error;
-use crate::toolset::{ResolveOptions, ToolRequest, ToolSource, Toolset};
+use crate::toolset::{ResolveOptions, ToolRequest, ToolSource, Toolset, tool_from_env_var_name};
 use crate::{config, env};
 
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
@@ -111,15 +111,7 @@ impl ToolsetBuilder {
             return Ok(());
         }
         for (k, v) in env {
-            if k.starts_with("MISE_") && k.ends_with("_VERSION") && k != "MISE_VERSION" {
-                let tool_name = k
-                    .trim_start_matches("MISE_")
-                    .trim_end_matches("_VERSION")
-                    .to_lowercase();
-                if tool_name == "install" || tool_name == "tool" {
-                    // ignore MISE_INSTALL_VERSION and MISE_TOOL_VERSION (set during hooks)
-                    continue;
-                }
+            if let Some(tool_name) = tool_from_env_var_name(&k) {
                 let ba: Arc<BackendArg> = Arc::new(tool_name.as_str().into());
                 let source = ToolSource::Environment(k, v.clone());
                 let mut env_ts = Toolset::new(source.clone());
diff --git a/src/toolset/mod.rs b/src/toolset/mod.rs
index ab1ade77f83..577b42da342 100644
--- a/src/toolset/mod.rs
+++ b/src/toolset/mod.rs
@@ -33,7 +33,9 @@ use tokio::sync::OnceCell;
 
 pub use install_options::InstallOptions;
 pub use tool_request::ToolRequest;
-pub use tool_request_set::{ToolRequestSet, ToolRequestSetBuilder, tool_env_vars};
+pub use tool_request_set::{
+    ToolRequestSet, ToolRequestSetBuilder, tool_env_var_name, tool_env_vars, tool_from_env_var_name,
+};
 pub use tool_source::ToolSource;
 pub use tool_version::{ResolveOptions, ToolVersion};
 pub use tool_version_list::ToolVersionList;
diff --git a/src/toolset/tool_request_set.rs b/src/toolset/tool_request_set.rs
index f7fdf0f45ba..a2a4405fd9b 100644
--- a/src/toolset/tool_request_set.rs
+++ b/src/toolset/tool_request_set.rs
@@ -10,6 +10,7 @@ use crate::config::{Config, ConfigMap, Settings};
 use crate::env;
 use crate::registry::{REGISTRY, tool_enabled};
 use crate::toolset::{ToolRequest, ToolSource, Toolset};
+use heck::{ToKebabCase, ToShoutySnakeCase};
 use indexmap::IndexMap;
 use itertools::Itertools;
 
@@ -300,23 +301,33 @@ fn merge(mut a: ToolRequestSet, mut b: ToolRequestSet) -> ToolRequestSet {
     b
 }
 
+/// Returns the environment variable used to select a tool version for a shell session.
+pub fn tool_env_var_name(tool: &str) -> String {
+    format!("MISE_{}_VERSION", tool.to_shouty_snake_case())
+}
+
+/// Returns the tool selected by a shell-session environment variable.
+///
+/// Shell environment variable names cannot preserve the distinction between `-` and `_`.
+/// Since mise tool names conventionally use kebab-case, both spellings decode to `-`.
+pub fn tool_from_env_var_name(name: &str) -> Option<String> {
+    if env::NON_TOOL_VERSION_ENV_VARS.contains(&name) {
+        return None;
+    }
+    let raw = name.strip_prefix("MISE_")?.strip_suffix("_VERSION")?;
+    if raw.is_empty() {
+        return None;
+    }
+    Some(crate::backend::unalias_backend(&raw.to_kebab_case()).to_string())
+}
+
 /// Yields `(short, key, value)` for each `MISE_<TOOL>_VERSION` env var that
 /// maps to a tool. `short` is the unaliased backend short name (so
 /// `MISE_NODEJS_VERSION` yields `"node"`). Skips `MISE_VERSION` and the
 /// `MISE_INSTALL_VERSION` / `MISE_TOOL_VERSION` vars set during hooks.
 pub fn tool_env_vars() -> impl Iterator<Item = (String, String, String)> {
     env::vars_safe().filter_map(|(k, v)| {
-        if !k.starts_with("MISE_") || !k.ends_with("_VERSION") || k == "MISE_VERSION" {
-            return None;
-        }
-        let raw = k
-            .trim_start_matches("MISE_")
-            .trim_end_matches("_VERSION")
-            .to_lowercase();
-        if raw == "install" || raw == "tool" {
-            return None;
-        }
-        let short = crate::backend::unalias_backend(&raw).to_string();
+        let short = tool_from_env_var_name(&k)?;
         Some((short, k, v))
     })
 }
@@ -326,6 +337,20 @@ mod tests {
     use super::*;
     use crate::toolset::{CoreToolOptions, ToolVersionOptions};
 
+    #[test]
+    fn test_tool_env_var_name_round_trip() {
+        assert_eq!(tool_env_var_name("ls-lint"), "MISE_LS_LINT_VERSION");
+        assert_eq!(
+            tool_from_env_var_name("MISE_LS_LINT_VERSION").as_deref(),
+            Some("ls-lint")
+        );
+        assert_eq!(tool_env_var_name("ls-lint"), tool_env_var_name("ls_lint"));
+        assert_eq!(
+            tool_from_env_var_name("MISE_NODEJS_VERSION").as_deref(),
+            Some("node")
+        );
+    }
+
     #[test]
     fn test_load_runtime_env_with_valid_utf8() {
         // This test verifies that valid UTF-8 MISE_*_VERSION variables work correctly
@@ -384,19 +409,19 @@ mod tests {
     fn test_tool_env_vars_skips_non_tool_vars() {
         unsafe {
             std::env::set_var("MISE_VERSION", "2026.4.28");
-            std::env::set_var("MISE_INSTALL_VERSION", "1.0.0");
-            std::env::set_var("MISE_TOOL_VERSION", "1.0.0");
+            std::env::set_var(env::MISE_INSTALL_VERSION_ENV_VAR, "1.0.0");
+            std::env::set_var(env::MISE_TOOL_VERSION_ENV_VAR, "1.0.0");
         }
 
         let keys: HashSet<String> = tool_env_vars().map(|(_, k, _)| k).collect();
         assert!(!keys.contains("MISE_VERSION"));
-        assert!(!keys.contains("MISE_INSTALL_VERSION"));
-        assert!(!keys.contains("MISE_TOOL_VERSION"));
+        assert!(!keys.contains(env::MISE_INSTALL_VERSION_ENV_VAR));
+        assert!(!keys.contains(env::MISE_TOOL_VERSION_ENV_VAR));
 
         unsafe {
             std::env::remove_var("MISE_VERSION");
-            std::env::remove_var("MISE_INSTALL_VERSION");
-            std::env::remove_var("MISE_TOOL_VERSION");
+            std::env::remove_var(env::MISE_INSTALL_VERSION_ENV_VAR);
+            std::env::remove_var(env::MISE_TOOL_VERSION_ENV_VAR);
         }
     }