diff --git a/changelog.md b/changelog.md
index 3663790..6bc710b 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,7 @@
 
 ## 0.2.4
 
+- Fixed: If note is played via a qwerty key press, and then an octave is changed via a qwerty key press, there won't be a note-off event.
 - Fixed: Cacophony can't found files (saves, soundfonts, etc.) if the file extension contains uppercase characters.
 - Fixed clippy warnings for Rust 1.78
 - The GitHub workflow for building Cacophony now uses the latest version of Rust.
diff --git a/input/src/lib.rs b/input/src/lib.rs
index d8f8bfc..d2ba7f4 100644
--- a/input/src/lib.rs
+++ b/input/src/lib.rs
@@ -70,9 +70,9 @@ pub struct Input {
     events: Vec<InputEvent>,
     /// The MIDI connection.
     midi_conn: Option<MidiConn>,
-    // Note-on MIDI messages. These will be sent immediately to the synthesizer to be played.
+    /// Note-on MIDI messages. These will be sent immediately to the synthesizer to be played.
     pub note_on_messages: Vec<[u8; 3]>,
-    // Note-off MIDI messages. These will be sent immediately to the synthesizer.
+    /// Note-off MIDI messages. These will be sent immediately to the synthesizer.
     pub note_off_keys: Vec<u8>,
     /// Note-on events that don't have corresponding off events.
     note_on_events: Vec<NoteOn>,
@@ -206,10 +206,12 @@ impl Input {
         }
         // Octave up.
         if events.contains(&InputEvent::OctaveUp) && self.qwerty_octave < MAX_OCTAVE {
+            self.clear_notes_on_qwerty_octave();
             self.qwerty_octave += 1;
         }
         // Octave down.
         if events.contains(&InputEvent::OctaveDown) && self.qwerty_octave > 0 {
+            self.clear_notes_on_qwerty_octave();
             self.qwerty_octave -= 1;
         }
         // Qwerty note-off.
@@ -420,6 +422,14 @@ impl Input {
         (9 - self.qwerty_octave) * 12 + note
     }
 
+    /// When a qwerty note is pressed, followed by an octave change, clear all note-on events.
+    fn clear_notes_on_qwerty_octave(&mut self) {
+        // Qwerty note-off.
+        for (_, qwerty_note_off) in QWERTY_NOTE_EVENTS.iter() {
+            self.note_off_keys.push(self.get_pitch(*qwerty_note_off));
+        }
+    }
+
     #[cfg(debug_assertions)]
     fn listen_for_note_offs(&mut self) {
         if self.happened(&InputEvent::NotesOff) {