diff --git a/CHANGES b/CHANGES
index ecbd0b5cc..d9f285676 100644
--- a/CHANGES
+++ b/CHANGES
@@ -64,6 +64,7 @@ Bugfixes:
  - GB Audio: Fix channel 1, 2 and 4 reset timing
  - Util: Fix wrapping edge cases in RingFIFO
  - GBA Hardware: Fix RTC handshake transition (fixes mgba.io/i/1134)
+ - GBA BIOS: Fix BitUnPack narrowing
 Misc:
  - GBA Timer: Use global cycles for timers
  - GBA: Extend oddly-sized ROMs to full address space (fixes mgba.io/i/722)
diff --git a/src/gba/bios.c b/src/gba/bios.c
index ead5332c2..b696169b6 100644
--- a/src/gba/bios.c
+++ b/src/gba/bios.c
@@ -820,7 +820,6 @@ static void _unBitPack(struct GBA* gba) {
 		in >>= sourceWidth;
 		if (scaled || bias & 0x80000000) {
 			scaled += bias & 0x7FFFFFFF;
-			scaled &= (1 << destWidth) - 1;
 		}
 		bitsRemaining -= sourceWidth;
 		out |= scaled << bitsEaten;
@@ -832,4 +831,6 @@ static void _unBitPack(struct GBA* gba) {
 			dest += 4;
 		}
 	}
+	cpu->gprs[0] = source;
+	cpu->gprs[1] = dest;
 }