diff --git a/src/sys/mako.h b/src/sys/mako.h
index b53f027..0a383fc 100644
--- a/src/sys/mako.h
+++ b/src/sys/mako.h
@@ -14,6 +14,11 @@
 #include "../common.h"
 #include "nact.h"
 
+enum BGMDevice {
+	BGM_FM,
+	BGM_CD
+};
+
 class MAKO
 {
 public:
@@ -29,7 +34,11 @@ public:
 	void stop_pcm();
 	bool check_pcm();
 
+	void set_cd_track(int num, int track) { cd_track[num] = track; }
+
 #ifdef _WIN32
+	void select_sound(BGMDevice dev);
+
 	void on_mci_notify(SDL_SysWMmsg* msg);
 #endif
 
@@ -39,10 +48,10 @@ public:
 
 	int current_music;
 	int next_loop;		// Y19
-	int cd_track[100];	// Z
 
 private:
 	NACT* nact;
+	int cd_track[100];	// Z
 
 #if !defined(__EMSCRIPTEN__) && !defined(__ANDROID__)
 	bool load_playlist(const char* path);
diff --git a/src/sys/nact.cpp b/src/sys/nact.cpp
index 4e3b497..efa4d1b 100644
--- a/src/sys/nact.cpp
+++ b/src/sys/nact.cpp
@@ -420,23 +420,6 @@ void NACT::select_cursor()
 	ags->select_cursor();
 }
 
-void NACT::select_sound(int dev)
-{
-	// 強制的に音源を変更する
-	int page = mako->current_music;
-	int old_dev = (1 <= page && page <= 99 && mako->cd_track[page]) ? 1 : 0;
-
-	for(int i = 1; i <= 99; i++) {
-		mako->cd_track[i] = dev ? i : 0;
-	}
-
-	// デバイスが変更された場合は再演奏する
-	if(dev != old_dev && page) {
-		mako->stop_music();
-		mako->play_music(page);
-	}
-}
-
 void NACT::fatal(const char* format, ...) {
 	char buf[512];
 	va_list args;
diff --git a/src/sys/nact.h b/src/sys/nact.h
index 2a91589..59c6a38 100644
--- a/src/sys/nact.h
+++ b/src/sys/nact.h
@@ -241,7 +241,6 @@ public:
 	int get_screen_height();
 
 	void select_cursor();
-	void select_sound(int dev);
 
 	const char* get_game_id();
 	static const int get_sys_ver(uint32 crc32_a, uint32 crc32_b);
diff --git a/src/sys/nact_sys3.cpp b/src/sys/nact_sys3.cpp
index b8e98df..f93ee8d 100644
--- a/src/sys/nact_sys3.cpp
+++ b/src/sys/nact_sys3.cpp
@@ -1526,7 +1526,7 @@ void NACT_Sys3::cmd_z()
 	} else if(cmd == 7) {
 		ags->cursor_color = (uint8)(param & 0xff);
 	} else if(101 <= cmd && cmd <= 199) {
-		mako->cd_track[cmd - 100] = param;
+		mako->set_cd_track(cmd - 100, param);
 	}
 }
 
diff --git a/src/win/mako.cpp b/src/win/mako.cpp
index 985be6b..83cc70e 100644
--- a/src/win/mako.cpp
+++ b/src/win/mako.cpp
@@ -304,6 +304,23 @@ bool MAKO::check_music()
 	return music && music->is_playing();
 }
 
+void MAKO::select_sound(BGMDevice dev)
+{
+	// 強制的に音源を変更する
+	int page = current_music;
+	int old_dev = (1 <= page && page <= 99 && cd_track[page]) ? BGM_CD : BGM_FM;
+
+	for (int i = 1; i <= 99; i++) {
+		cd_track[i] = (dev == BGM_CD) ? i : 0;
+	}
+
+	// デバイスが変更された場合は再演奏する
+	if (dev != old_dev && page) {
+		stop_music();
+		play_music(page);
+	}
+}
+
 void MAKO::get_mark(int* mark, int* loop)
 {
 	// TODO: fix
diff --git a/src/win/nact_win.cpp b/src/win/nact_win.cpp
index 1b745c5..5027378 100644
--- a/src/win/nact_win.cpp
+++ b/src/win/nact_win.cpp
@@ -150,10 +150,10 @@ void NACT::on_syswmevent(SDL_SysWMmsg* msg)
 			ags->flush_screen(true);
 			break;
 		case ID_SOUND_FM:
-			select_sound(0);
+			mako->select_sound(BGM_FM);
 			break;
 		case ID_SOUND_CD:
-			select_sound(1);
+			mako->select_sound(BGM_CD);
 			break;
 		case ID_TEXT_SKIP:
 			text_skip_enb = !text_skip_enb;