diff --git a/firmware/src/key_codes.rs b/firmware/src/key_codes.rs
index 4bca6b0..da8eb21 100644
--- a/firmware/src/key_codes.rs
+++ b/firmware/src/key_codes.rs
@@ -5,6 +5,7 @@ use defmt::Format;
 #[derive(Copy, Clone, Format, PartialEq)]
 pub enum KeyCode {
     Empty = 0x0,
+    ErrorRollOver = 0x01,
     A = 0x04,
     B = 0x05,
     C = 0x06,
diff --git a/firmware/src/key_scan.rs b/firmware/src/key_scan.rs
index 1dc68e2..b6aa000 100644
--- a/firmware/src/key_scan.rs
+++ b/firmware/src/key_scan.rs
@@ -83,6 +83,10 @@ impl<const NUM_ROWS: usize, const NUM_COLS: usize> From<KeyScan<NUM_ROWS, NUM_CO
             if keycode_index < keycodes.len() {
                 keycodes[keycode_index] = key;
                 keycode_index += 1;
+            } else {
+                for keycode in &mut keycodes {
+                    *keycode = KeyCode::ErrorRollOver as u8;
+                }
             }
         };