diff --git a/core/src/iodev.rs b/core/src/iodev.rs
index 282a434..bb51870 100644
--- a/core/src/iodev.rs
+++ b/core/src/iodev.rs
@@ -304,9 +304,9 @@ impl BusIO for IoDevices {
     fn write_8(&mut self, addr: Addr, value: u8) {
         match addr + IO_BASE {
             /* FIFO_A */
-            0x0400_00A0..=0x0400_00A3 => self.sound.write_fifo(0, value as i8),
+            0x0400_00A0 | 0x0400_00A1 | 0x0400_00A2 | 0x0400_00A3 => { self.sound.write_fifo(0, value as i8) }
             /* FIFO_B */
-            0x0400_00A4..=0x0400_00A7 => self.sound.write_fifo(1, value as i8),
+            0x0400_00A4 | 0x0400_00A5 | 0x0400_00A6 | 0x0400_00A7 => { self.sound.write_fifo(1, value as i8) }
             _ => {
                 let t = self.read_16(addr & !1);
                 let t = if addr & 1 != 0 {