diff --git a/src/profile.rs b/src/profile.rs
index c518471..fc0190f 100644
--- a/src/profile.rs
+++ b/src/profile.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, HashSet};
 use std::path::{Path, PathBuf};
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct Profile {
     pub name: String,
     #[serde(default = "default_client")]
@@ -63,10 +63,14 @@ fn default_mode() -> Mode {
     Mode::Maps
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, Default,
+    Serialize, Deserialize,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum Mode {
     /// 1: only configured maps; everything else goes to the front window
+    #[default]
     Maps,
     /// 2: clone keys to the other game windows (front window still gets the real key)
     #[serde(alias = "repeater")]
diff --git a/src/session.rs b/src/session.rs
index db3fafb..545dab1 100644
--- a/src/session.rs
+++ b/src/session.rs
@@ -1252,6 +1252,43 @@ mod tests {
         }
     }
 
+    #[test]
+    fn mouse_repeat_ms_clamps_env_var() {
+        // The default cadence is 50 ms when the env var is unset
+        // or malformed; explicit values in [1, 2000] pass through;
+        // out-of-range values fall back to 50. We assert the bounds
+        // by reading back Session.mouse_repeat_ms as a u64 from
+        // a constructed Session (Session::new does the parse).
+        for raw in ["1", "50", "2000"] {
+            std::env::set_var("ENBOXER_MOUSE_REPEAT_MS", raw);
+            let s = Session::new(
+                crate::profile::Profile::default(),
+                std::path::PathBuf::from("/bin/true"),
+                std::path::PathBuf::from("/tmp/enboxer-test.sock"),
+            )
+            .expect("Session::new should succeed for a valid profile");
+            let v: u64 = raw.parse().unwrap();
+            assert_eq!(
+                s.mouse_repeat_ms, v,
+                "ENBOXER_MOUSE_REPEAT_MS={raw} should pass through"
+            );
+        }
+        for raw in ["0", "2001", "not_a_number", ""] {
+            std::env::set_var("ENBOXER_MOUSE_REPEAT_MS", raw);
+            let s = Session::new(
+                crate::profile::Profile::default(),
+                std::path::PathBuf::from("/bin/true"),
+                std::path::PathBuf::from("/tmp/enboxer-test.sock"),
+            )
+            .expect("Session::new should succeed for a valid profile");
+            assert_eq!(
+                s.mouse_repeat_ms, 50,
+                "ENBOXER_MOUSE_REPEAT_MS={raw} should fall back to 50"
+            );
+        }
+        std::env::remove_var("ENBOXER_MOUSE_REPEAT_MS");
+    }
+
     #[test]
     fn others_excludes_leader() {
         let slots = vec![