diff --git a/sud.c b/sud.c
index 4d84a22..f14b20f 100644
--- a/sud.c
+++ b/sud.c
@@ -54,29 +54,20 @@ enum update_res update(struct sudoku *sud, unsigned r, unsigned c, unsigned val)
 	unsigned tr, tc;
 	const uint16_t clearmask = ~(1 << val);
 
-	/* Update possible values of cells in same column. */
-	for (tr = 0; tr < NDIGITS; ++tr) {
-		if (tr == r || DET(sud->cells[tr][c]))
-			continue;
-		sud->cells[tr][c] &= clearmask;
-	}
-
 	/* Update possible values of cells in same row. */
-	for (tc = 0; tc < NDIGITS; ++tc) {
-		if (tc == c || DET(sud->cells[r][tc]))
-			continue;
+	for (tc = 0; tc < NDIGITS; ++tc)
 		sud->cells[r][tc] &= clearmask;
-	}
+
+	/* Update possible values of cells in same column. */
+	for (tr = 0; tr < NDIGITS; ++tr)
+		sud->cells[tr][c] &= clearmask;
 
 	/* Update possible values of cells in same segment. */
 	const unsigned segr0 = SEGLEN * (r / SEGLEN);
 	const unsigned segc0 = SEGLEN * (c / SEGLEN);
 	for (tr = segr0; tr < segr0 + SEGLEN; ++tr) {
-		for (tc = segc0; tc < segc0 + SEGLEN; ++tc) {
-			if ((tr == r && tc == c) || DET(sud->cells[tr][tc]))
-				continue;
+		for (tc = segc0; tc < segc0 + SEGLEN; ++tc)
 			sud->cells[tr][tc] &= clearmask;
-		}
 	}
 
 	/* Set the cell's value. */