diff --git a/CHANGES b/CHANGES
index 2701b9b06..1f87ac339 100644
--- a/CHANGES
+++ b/CHANGES
@@ -52,6 +52,7 @@ Bugfixes:
  - Debugger: Fix binary print putting spaces between digits
  - GBA BIOS: Fix LZ77UnCompVram to use 16-bit loads from decompressed memory
  - GBA BIOS: Fix HuffUnComp to work when games pass an invalid bit length
+ - GBA BIOS: Fix GetBiosChecksum to return the value of a real GBA, regardless of used BIOS
 Misc:
  - Qt: Disable sync to video by default
  - GBA: Exit cleanly on FATAL if the port supports it
diff --git a/src/gba/gba-bios.c b/src/gba/gba-bios.c
index 631cff29a..91011b406 100644
--- a/src/gba/gba-bios.c
+++ b/src/gba/gba-bios.c
@@ -215,7 +215,10 @@ void GBASwi16(struct ARMCore* cpu, int immediate) {
 		ARMRaiseSWI(cpu);
 		break;
 	case 0xD:
-		cpu->gprs[0] = GBAChecksum(gba->memory.bios, SIZE_BIOS);
+		cpu->gprs[0] = GBA_BIOS_CHECKSUM;
+		cpu->gprs[1] = 1;
+		cpu->gprs[3] = SIZE_BIOS;
+		break;
 	case 0xE:
 		_BgAffineSet(gba);
 		break;