diff --git a/th01/resident.hpp b/th01/resident.hpp
index e57e8b43..d05221aa 100644
--- a/th01/resident.hpp
+++ b/th01/resident.hpp
@@ -4,11 +4,11 @@ typedef enum {
 	ROUTE_COUNT,
 } route_t;
 
-typedef enum {
-	MODE_REGULAR = 0,
-	MODE_TEST = 1,
-	MODE_DEBUG = 3
-} mode_t;
+enum debug_mode_t {
+	DM_OFF = 0,
+	DM_TEST = 1,
+	DM_FULL = 3
+};
 
 // Much like subpixels, pellet speeds are stored pre-multiplied by 40 to allow
 // an effective resolution of 0.025 pixels to be losslessly stored in an
@@ -34,7 +34,7 @@ typedef struct {
 	char rem_lives;
 	char snd_need_init;
 	char unused_2;
-	char mode;
+	debug_mode_t debug_mode;
 	pellet_speed_t pellet_speed;
 	long rand;
 	long score;
diff --git a/th01/th01.inc b/th01/th01.inc
index 2fa1ee22..5df5a5db 100644
--- a/th01/th01.inc
+++ b/th01/th01.inc
@@ -29,6 +29,10 @@ REGS		ends
 
 SCENE_COUNT = 4
 
+DM_OFF = 0
+DM_TEST = 1
+DM_FULL = 3
+
 reiidenconfig_t struc ; (sizeof=0x4B)
 	id db 13 dup(?)	; = "ReiidenConfig"
 		db ?
@@ -42,7 +46,7 @@ reiidenconfig_t struc ; (sizeof=0x4B)
 	rem_lives db ?
 	snd_need_init db ?
 	unused_2 db ?
-	mode db ?	; 0 = regular, 1 = test, 3 = debug
+	debug_mode db ?
 	bullet_speed dw ?
 	rand  dd ?
 	score dd ?
diff --git a/th01_op.asm b/th01_op.asm
index 9c52e7c4..0b37bd0f 100644
--- a/th01_op.asm
+++ b/th01_op.asm
@@ -172,7 +172,7 @@ sub_A7B5	proc far
 		cmp	ax, 2
 		jnz	short loc_A7FC
 		les	bx, _resident
-		mov	es:[bx+reiidenconfig_t.mode], 1
+		mov	es:[bx+reiidenconfig_t.debug_mode], DM_TEST
 		jmp	short loc_A820
 ; ---------------------------------------------------------------------------
 
@@ -182,7 +182,7 @@ loc_A7FC:
 		cmp	ax, 3
 		jnz	short loc_A810
 		les	bx, _resident
-		mov	es:[bx+reiidenconfig_t.mode], 3
+		mov	es:[bx+reiidenconfig_t.debug_mode], DM_FULL
 		jmp	short loc_A820
 ; ---------------------------------------------------------------------------
 
@@ -190,7 +190,7 @@ loc_A810:
 		cmp	_mode, 0
 		jnz	short loc_A820
 		les	bx, _resident
-		mov	es:[bx+reiidenconfig_t.mode], 0
+		mov	es:[bx+reiidenconfig_t.debug_mode], DM_OFF
 
 loc_A820:
 		les	bx, _resident
@@ -262,7 +262,7 @@ loc_A8E1:
 		call	_game_switch_binary
 		les	bx, _resident
 		assume es:nothing
-		mov	es:[bx+reiidenconfig_t.mode], 0
+		mov	es:[bx+reiidenconfig_t.debug_mode], DM_OFF
 		mov	es:[bx+reiidenconfig_t.snd_need_init], 1
 		mov	al, _opts.O_lives_extra
 		add	al, 2
diff --git a/th01_reiiden.asm b/th01_reiiden.asm
index 4bd7c4d0..c233c7f6 100644
--- a/th01_reiiden.asm
+++ b/th01_reiiden.asm
@@ -2342,7 +2342,7 @@ loc_D583:
 		les	bx, _resident
 		mov	al, es:[bx+reiidenconfig_t.route]
 		mov	_route, al
-		cmp	es:[bx+reiidenconfig_t.mode], 0
+		cmp	es:[bx+reiidenconfig_t.debug_mode], DM_OFF
 		jz	loc_D68E
 		cmp	es:[bx+reiidenconfig_t.stage], 0
 		jnz	short loc_D649
@@ -2396,9 +2396,9 @@ loc_D644:
 
 loc_D649:
 		les	bx, _resident
-		mov	al, es:[bx+reiidenconfig_t.mode]
+		mov	al, es:[bx+reiidenconfig_t.debug_mode]
 		cbw
-		cmp	ax, 1
+		cmp	ax, DM_TEST
 		jnz	short loc_D669
 		push	ds
 		push	offset aGegxgggvbGhbib ; "テストモード！！\n"
@@ -2408,9 +2408,9 @@ loc_D649:
 
 loc_D669:
 		les	bx, _resident
-		mov	al, es:[bx+reiidenconfig_t.mode]
+		mov	al, es:[bx+reiidenconfig_t.debug_mode]
 		cbw
-		cmp	ax, 3
+		cmp	ax, DM_FULL
 		jnz	short loc_D68E
 		push	ds
 		push	offset aGfgogbgogvbGhb ; "デバッグモード！！\n"