diff --git a/src/main.c b/src/main.c
index f0e9900..df1eaca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -7,7 +7,7 @@
 
 int main(int argc, char **argv) {
 	(void)argc, (void)argv;
-	u16 board[SUDOKU_DEPTH_2] = {
+	u16 board[SUDOKU_LEN] = {
 		// clang-format off
 		0x010, 0x004, 0x000, 0x000, 0x040, 0x000, 0x000, 0x000, 0x000,
 		0x020, 0x000, 0x000, 0x001, 0x100, 0x010, 0x000, 0x000, 0x000,
diff --git a/src/sudoku.c b/src/sudoku.c
index b20abc1..02e61ef 100644
--- a/src/sudoku.c
+++ b/src/sudoku.c
@@ -14,18 +14,18 @@ static inline void setbrdpos(u16 *brd, u16 val) {
 }
 
 void sudoku_place(u16 *brd, u16 val, uint idx) {
-	uint icol = idx % SUDOKU_DEPTH;
+	uint icol = idx % SUDOKU_DPT;
 	uint irow = idx - icol;
-	uint ibox = idx - (idx % SUDOKU_DEPTH_SQRT);
-	for (uint i = 0; i < SUDOKU_DEPTH; i++) {
+	uint ibox = idx - (idx % SUDOKU_BOXLEN);
+	for (uint i = 0; i < SUDOKU_DPT; i++) {
 		setbrdpos(&brd[irow + i], val);
-		setbrdpos(&brd[icol + (i * SUDOKU_DEPTH)], val);
-		setbrdpos(&brd[ibox + (i / SUDOKU_DEPTH_SQRT * SUDOKU_DEPTH) + (i % SUDOKU_DEPTH_SQRT)], val);
+		setbrdpos(&brd[icol + (i * SUDOKU_DPT)], val);
+		setbrdpos(&brd[ibox + (i / SUDOKU_BOXLEN * SUDOKU_DPT) + (i % SUDOKU_BOXLEN)], val);
 	}
 }
 
 void sudoku_solve_step(u16 *board) {
-	for (uint i = 0; i < SUDOKU_DEPTH_2; i++) {
+	for (uint i = 0; i < SUDOKU_LEN; i++) {
 		board[i] |= SUDOKU_ALL & -!board[i];
 
 		switch (board[i]) {
@@ -45,7 +45,7 @@ void sudoku_solve_step(u16 *board) {
 
 void sudoku_print(const u16 *board) {
 	printf("+———-———-———-———-———-———-———-———-———+\n");
-	for (uint i = 0; i < SUDOKU_DEPTH_2; i++) {
+	for (uint i = 0; i < SUDOKU_LEN; i++) {
 		char tile;
 		switch (board[i]) {
 		case 0:        tile = 'x'; break;
diff --git a/src/sudoku.h b/src/sudoku.h
index b9df4c3..d49e62f 100644
--- a/src/sudoku.h
+++ b/src/sudoku.h
@@ -4,9 +4,9 @@
 
 #include "util/intdef.h"
 
-#define SUDOKU_DEPTH_SQRT 3
-#define SUDOKU_DEPTH      (SUDOKU_DEPTH_SQRT * SUDOKU_DEPTH_SQRT)
-#define SUDOKU_DEPTH_2    (SUDOKU_DEPTH * SUDOKU_DEPTH)
+#define SUDOKU_BOXLEN     3
+#define SUDOKU_DPT        9
+#define SUDOKU_LEN        (SUDOKU_DPT * SUDOKU_DPT)
 
 /* bitmask  */
 enum sudoku_bitmask {