diff --git a/ReC98.h b/ReC98.h
index 7a7b9c89..24919f3e 100644
--- a/ReC98.h
+++ b/ReC98.h
@@ -11,29 +11,4 @@
 #include "pc98.h"
 #include "planar.h"
 
-// Macros
-// ------
-#ifdef __cplusplus
-	// This is, in fact, the only way to circumvent 16-bit promotion inside
-	// comparisons between two 8-bit values in C++. I kid you not.
-	static inline char ring_min() {
-		return 0;
-	}
-#else
-	#define ring_min() 0
-#endif
-
-#define RING_INC(val, ring_end) \
-	(val)++; \
-	if((val) > (ring_end)) { \
-		(val) = 0; \
-	}
-
-#define RING_DEC(val, ring_end) \
-	(val)--; \
-	if(val < ring_min()) { \
-		(val) = ring_end; \
-	}
-// ------
-
 #endif /* REC98_H */
diff --git a/th01/math/clamp.hpp b/th01/math/clamp.hpp
index 4fc712ce..7b0d9af4 100644
--- a/th01/math/clamp.hpp
+++ b/th01/math/clamp.hpp
@@ -18,3 +18,25 @@
 	if((v) < (min)) { \
 		(v) = (min); \
 	}
+
+#ifdef __cplusplus
+	// This is, in fact, the only way to circumvent 16-bit promotion inside
+	// comparisons between two 8-bit values in C++. I kid you not.
+	static inline char ring_min() {
+		return 0;
+	}
+#else
+	#define ring_min() 0
+#endif
+
+#define ring_inc(val, ring_end) \
+	(val)++; \
+	if((val) > (ring_end)) { \
+		(val) = 0; \
+	}
+
+#define ring_dec(val, ring_end) \
+	(val)--; \
+	if(val < ring_min()) { \
+		(val) = ring_end; \
+	}
diff --git a/th02/maine_04.cpp b/th02/maine_04.cpp
index 4742c22f..4e769d3b 100644
--- a/th02/maine_04.cpp
+++ b/th02/maine_04.cpp
@@ -193,16 +193,16 @@ void pascal score_enter(void)
 		input_sense();
 		if(!input_locked) {
 			if(key_det & INPUT_UP) {
-				alphabet_cursor_move(row, ALPHABET_ROWS, RING_DEC, col, row);
+				alphabet_cursor_move(row, ALPHABET_ROWS, ring_dec, col, row);
 			}
 			if(key_det & INPUT_DOWN) {
-				alphabet_cursor_move(row, ALPHABET_ROWS, RING_INC, col, row);
+				alphabet_cursor_move(row, ALPHABET_ROWS, ring_inc, col, row);
 			}
 			if(key_det & INPUT_LEFT) {
-				alphabet_cursor_move(col, ALPHABET_COLS, RING_DEC, col, row);
+				alphabet_cursor_move(col, ALPHABET_COLS, ring_dec, col, row);
 			}
 			if(key_det & INPUT_RIGHT) {
-				alphabet_cursor_move(col, ALPHABET_COLS, RING_INC, col, row);
+				alphabet_cursor_move(col, ALPHABET_COLS, ring_inc, col, row);
 			}
 			if(key_det & INPUT_SHOT || key_det & INPUT_OK) {
 				/* Yeah, it sucks that ZUN checks against the indices into the
diff --git a/th02/op_01.cpp b/th02/op_01.cpp
index cc6f8977..778afa88 100644
--- a/th02/op_01.cpp
+++ b/th02/op_01.cpp
@@ -10,6 +10,7 @@ extern "C" {
 #include "th02/resident.hpp"
 #include "master.hpp"
 #include "libs/kaja/kaja.h"
+#include "th01/math/clamp.hpp"
 #include "th02/hardware/frmdelay.h"
 #include "th02/hardware/grp_rect.h"
 #include "th02/hardware/input.hpp"
@@ -585,10 +586,10 @@ void option_update_and_render(void)
 			menu_sel_move(6, 1);
 		}
 		if(key_det & INPUT_RIGHT) {
-			option_change(RING_INC);
+			option_change(ring_inc);
 		}
 		if(key_det & INPUT_LEFT) {
-			option_change(RING_DEC);
+			option_change(ring_dec);
 		}
 		if(key_det & INPUT_SHOT || key_det & INPUT_OK) {
 			switch(menu_sel) {
diff --git a/th02/op_05.cpp b/th02/op_05.cpp
index f7760098..f2497a2d 100644
--- a/th02/op_05.cpp
+++ b/th02/op_05.cpp
@@ -7,6 +7,7 @@ extern "C" {
 #include "th02/th02.h"
 #include "x86real.h"
 #include "master.hpp"
+#include "th01/math/clamp.hpp"
 #include "th02/resident.hpp"
 #include "th02/hardware/frmdelay.h"
 #include "th02/hardware/grp_rect.h"
@@ -188,7 +189,7 @@ void pascal shottype_menu(void)
 				frame_delay(1);
 				darken_pic_at(pic_x[sel] + 8, pic_y[sel] + 8);
 
-				RING_DEC(sel, sel_ring_end());
+				ring_dec(sel, sel_ring_end());
 				draw_new_sel(pic_x, pic_y);
 			}
 			if(key_det & INPUT_RIGHT) {
@@ -200,7 +201,7 @@ void pascal shottype_menu(void)
 				frame_delay(1);
 				darken_pic_at(pic_x[sel] + 8, pic_y[sel] + 8);
 
-				RING_INC(sel, sel_ring_end());
+				ring_inc(sel, sel_ring_end());
 				draw_new_sel(pic_x, pic_y);
 			}
 			if(key_det & INPUT_SHOT || key_det & INPUT_OK) {