@@ -28,6 +28,10 @@ struct GBAVideoRenderer;
 
 extern const int GBA_LUX_LEVELS[10];
 
+enum {
+	mPERIPH_GBA_LUMINANCE = 0x1000
+};
+
 struct GBALuminanceSource {
 	void (*sample)(struct GBALuminanceSource*);
 

@@ -298,7 +298,7 @@ GUIShowMessageBox(&runner->params, GUI_MESSAGE_BOX_OK, 240, "Load failed!");
 		return;
 	}
 	if (runner->core->platform(runner->core) == PLATFORM_GBA) {
-		((struct GBA*) runner->core->board)->luminanceSource = &runner->luminanceSource.d;
+		runner->core->setPeripheral(runner->core, mPERIPH_GBA_LUMINANCE, &runner->luminanceSource.d);
 	}
 	mLOG(GUI_RUNNER, DEBUG, "Loading config...");
 	mCoreLoadForeignConfig(runner->core, &runner->config);

@@ -414,6 +414,9 @@ break;
 	case mPERIPH_RUMBLE:
 		gba->rumble = periph;
 		break;
+	case mPERIPH_GBA_LUMINANCE:
+		gba->luminanceSource = periph;
+		break;
 	default:
 		return;
 	}

@@ -409,8 +409,7 @@ core->loadSave(core, save);
 
 #ifdef M_CORE_GBA
 	if (core->platform(core) == PLATFORM_GBA) {
-		struct GBA* gba = core->board;
-		gba->luminanceSource = &lux;
+		core->setPeripheral(core, mPERIPH_GBA_LUMINANCE, &lux);
 
 		const char* sysDir = 0;
 		if (core->opts.useBios && environCallback(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &sysDir)) {

@@ -99,7 +99,7 @@ #endif
 		switch (context->core->platform(context->core)) {
 #ifdef M_CORE_GBA
 		case PLATFORM_GBA:
-			gba->luminanceSource = &controller->m_lux;
+			context->core->setPeripheral(context->core, mPERIPH_GBA_LUMINANCE, &controller->m_lux);
 			gba->audio.psg.forceDisableCh[0] = !controller->m_audioChannels[0];
 			gba->audio.psg.forceDisableCh[1] = !controller->m_audioChannels[1];
 			gba->audio.psg.forceDisableCh[2] = !controller->m_audioChannels[2];