diff --git a/crates/maestro-tui/src/config.rs b/crates/maestro-tui/src/config.rs
index 9f4eb2b..790e6bd 100644
--- a/crates/maestro-tui/src/config.rs
+++ b/crates/maestro-tui/src/config.rs
@@ -238,6 +238,26 @@ mod tests {
         assert!(s.contains("ctrl-glorb"), "diagnostic: {s}");
     }
 
+    /// Regression for #70: the previous canonical form of a real Shift+S
+    /// keypress was `"shift-S"`, which the default `"S"` binding never
+    /// matched. Drive the actual crossterm event, not the binding string,
+    /// so the dead-key bug can't come back unnoticed.
+    #[test]
+    fn real_shift_s_keypress_resolves_to_fast_forward_spawn() {
+        use crossterm::event::{Event as CtEvent, KeyCode, KeyEvent, KeyModifiers};
+
+        use crate::input::{canonicalise, Region};
+
+        let cfg = TuiConfig::load(&TuiSection::default()).unwrap();
+        let ev = CtEvent::Key(KeyEvent::new(KeyCode::Char('S'), KeyModifiers::SHIFT));
+        let key = canonicalise(&ev, |_, _| Region::Unknown).expect("key event canonicalises");
+
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Normal, &key.canonical()),
+            Some(Action::FastForwardSpawn),
+        );
+    }
+
     #[test]
     fn custom_chord_timeout_is_applied() {
         let mut section = TuiSection::default();
diff --git a/crates/maestro-tui/src/input.rs b/crates/maestro-tui/src/input.rs
index 34c4d4a..137458f 100644
--- a/crates/maestro-tui/src/input.rs
+++ b/crates/maestro-tui/src/input.rs
@@ -117,7 +117,9 @@ impl InputKey {
                 if *alt {
                     out.push_str("alt-");
                 }
-                if *shift {
+                // Uppercase already implies shift; crossterm sets the flag
+                // on every such char, so skip the redundant prefix (#70).
+                if *shift && !c.is_uppercase() {
                     out.push_str("shift-");
                 }
                 out.push(*c);
@@ -580,12 +582,28 @@ mod tests {
 
     #[test]
     fn canonical_round_trips_simple_chars() {
-        for s in ["a", "ctrl-a", "ctrl-w", "alt-x", "shift-A"] {
+        for s in ["a", "ctrl-a", "ctrl-w", "alt-x"] {
             let k = InputKey::parse(s).unwrap();
             assert_eq!(k.canonical(), s, "round-trip {s:?}");
         }
     }
 
+    /// crossterm 0.28 attaches `KeyModifiers::SHIFT` to any uppercase char,
+    /// so a real Shift+S delivers `Char { c: 'S', shift: true }`. Its
+    /// canonical form must be the bare `"S"` a keymap binds, not `"shift-S"` —
+    /// the uppercase letter already says "shifted"; a redundant prefix would
+    /// make the default `S` binding unreachable from the keyboard (#70).
+    #[test]
+    fn shift_flag_is_redundant_for_an_already_uppercase_char() {
+        let k = InputKey::Char {
+            c: 'S',
+            ctrl: false,
+            alt: false,
+            shift: true,
+        };
+        assert_eq!(k.canonical(), "S");
+    }
+
     #[test]
     fn canonical_round_trips_specials() {
         for s in [