diff --git a/include/mgba/internal/ds/video.h b/include/mgba/internal/ds/video.h
index 395114fc1..be0d6c0f5 100644
--- a/include/mgba/internal/ds/video.h
+++ b/include/mgba/internal/ds/video.h
@@ -66,6 +66,10 @@ DECL_BIT(DSRegisterPOWCNT1, Swap, 15);
 
 DECL_BIT(GBARegisterBGCNT, ExtPaletteSlot, 13);
 
+DECL_BITFIELD(DSRegisterMASTER_BRIGHT, uint16_t);
+DECL_BITS(DSRegisterMASTER_BRIGHT, Y, 0, 5);
+DECL_BITS(DSRegisterMASTER_BRIGHT, Mode, 14, 2);
+
 struct DSVideoRenderer {
 	void (*init)(struct DSVideoRenderer* renderer);
 	void (*reset)(struct DSVideoRenderer* renderer);
diff --git a/include/mgba/internal/gba/renderers/video-software.h b/include/mgba/internal/gba/renderers/video-software.h
index 93729374e..813da5e7a 100644
--- a/include/mgba/internal/gba/renderers/video-software.h
+++ b/include/mgba/internal/gba/renderers/video-software.h
@@ -167,6 +167,9 @@ struct GBAVideoSoftwareRenderer {
 	int masterEnd;
 	int masterHeight;
 	int masterScanlines;
+
+	int masterBright;
+	int masterBrightY;
 };
 
 void GBAVideoSoftwareRendererCreate(struct GBAVideoSoftwareRenderer* renderer);
diff --git a/src/ds/io.c b/src/ds/io.c
index a5939cefc..cf5355a90 100644
--- a/src/ds/io.c
+++ b/src/ds/io.c
@@ -422,9 +422,9 @@ void DS9IOInit(struct DS* ds) {
 }
 
 void DS9IOWrite(struct DS* ds, uint32_t address, uint16_t value) {
-	if (address <= DS9_REG_A_BLDY && (address > DS_REG_VCOUNT || address == DS9_REG_A_DISPCNT_LO || address == DS9_REG_A_DISPCNT_HI)) {
+	if ((address <= DS9_REG_A_BLDY && address > DS_REG_VCOUNT) || address == DS9_REG_A_DISPCNT_LO || address == DS9_REG_A_DISPCNT_HI || address == DS9_REG_A_MASTER_BRIGHT) {
 		value = ds->video.renderer->writeVideoRegister(ds->video.renderer, address, value);
-	} else if (address >= DS9_REG_B_DISPCNT_LO && address <= DS9_REG_B_BLDY) {
+	} else if ((address >= DS9_REG_B_DISPCNT_LO && address <= DS9_REG_B_BLDY) || address == DS9_REG_B_MASTER_BRIGHT) {
 		value = ds->video.renderer->writeVideoRegister(ds->video.renderer, address, value);
 	} else if ((address >= DS9_REG_RDLINES_COUNT && address <= DS9_REG_VECMTX_RESULT_12) || address == DS9_REG_DISP3DCNT) {
 		value = DSGXWriteRegister(&ds->gx, address, value);
diff --git a/src/ds/renderers/software.c b/src/ds/renderers/software.c
index e3b6c9d9d..cbfa776c0 100644
--- a/src/ds/renderers/software.c
+++ b/src/ds/renderers/software.c
@@ -270,6 +270,20 @@ static uint16_t DSVideoSoftwareRendererWriteVideoRegister(struct DSVideoRenderer
 	case DS9_REG_B_BG3CNT:
 		_updateCharBase(softwareRenderer, true);
 		break;
+	case DS9_REG_A_MASTER_BRIGHT:
+		softwareRenderer->engA.masterBright = DSRegisterMASTER_BRIGHTGetMode(value);
+		softwareRenderer->engA.masterBrightY = DSRegisterMASTER_BRIGHTGetY(value);
+		if (softwareRenderer->engA.masterBrightY > 0x10) {
+			softwareRenderer->engA.masterBrightY = 0x10;
+		}
+		break;
+	case DS9_REG_B_MASTER_BRIGHT:
+		softwareRenderer->engB.masterBright = DSRegisterMASTER_BRIGHTGetMode(value);
+		softwareRenderer->engB.masterBrightY = DSRegisterMASTER_BRIGHTGetY(value);
+		if (softwareRenderer->engB.masterBrightY > 0x10) {
+			softwareRenderer->engB.masterBrightY = 0x10;
+		}
+		break;
 	case DS9_REG_A_DISPCNT_LO:
 		softwareRenderer->dispcntA &= 0xFFFF0000;
 		softwareRenderer->dispcntA |= value;
@@ -323,9 +337,9 @@ static void DSVideoSoftwareRendererInvalidateExtPal(struct DSVideoRenderer* rend
 static void DSVideoSoftwareRendererDrawGBAScanline(struct GBAVideoRenderer* renderer, int y) {
 	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
 
+	int x;
 	color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
 	if (GBARegisterDISPCNTIsForcedBlank(softwareRenderer->dispcnt)) {
-		int x;
 		for (x = 0; x < softwareRenderer->masterEnd; ++x) {
 			row[x] = GBA_COLOR_WHITE;
 		}
@@ -406,7 +420,22 @@ static void DSVideoSoftwareRendererDrawGBAScanline(struct GBAVideoRenderer* rend
 	}
 #endif
 #else
-	memcpy(row, softwareRenderer->row, softwareRenderer->masterEnd * sizeof(*row));
+	switch (softwareRenderer->masterBright) {
+	case 0:
+	default:
+		memcpy(row, softwareRenderer->row, softwareRenderer->masterEnd * sizeof(*row));
+		break;
+	case 1:
+		for (x = 0; x < softwareRenderer->masterEnd; ++x) {
+			row[x] = _brighten(softwareRenderer->row[x], softwareRenderer->masterBrightY);
+		}
+		break;
+	case 2:
+		for (x = 0; x < softwareRenderer->masterEnd; ++x) {
+			row[x] = _darken(softwareRenderer->row[x], softwareRenderer->masterBrightY);
+		}
+		break;
+	}
 #endif
 }
 
diff --git a/src/gba/renderers/video-software.c b/src/gba/renderers/video-software.c
index 91ab27035..6d6315684 100644
--- a/src/gba/renderers/video-software.c
+++ b/src/gba/renderers/video-software.c
@@ -95,6 +95,8 @@ static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer) {
 	softwareRenderer->target2Obj = 0;
 	softwareRenderer->target2Bd = 0;
 	softwareRenderer->blendEffect = BLEND_NONE;
+	softwareRenderer->masterBright = 0;
+	softwareRenderer->masterBrightY = 0;
 	for (i = 0; i < 1024; i += 2) {
 		uint16_t entry;
 		LOAD_16(entry, i, softwareRenderer->d.palette);