diff --git a/src/gba/gba-io.c b/src/gba/gba-io.c
index 53c5863c1..6bd7a5ddf 100644
--- a/src/gba/gba-io.c
+++ b/src/gba/gba-io.c
@@ -135,7 +135,8 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
 			break;
 		case REG_SOUND3CNT_X:
 			GBAAudioWriteSOUND3CNT_X(&gba->audio, value);
-			value &= 0x4000;
+			// TODO: The low bits need to not be readable, but still 8-bit writable
+			value &= 0x43FF;
 			break;
 		case REG_SOUND4CNT_LO:
 			GBAAudioWriteSOUND4CNT_LO(&gba->audio, value);