diff --git a/chess_paths/chess_paths.c b/chess_paths/chess_paths.c
index 5670a20..31957e3 100644
--- a/chess_paths/chess_paths.c
+++ b/chess_paths/chess_paths.c
@@ -199,12 +199,12 @@ void rook_positions(struct search_status* s, struct piece_position* p) {
     unsigned c_cols = columns(s->chessboard);
     unsigned c_rows = rows(s->chessboard);
 
-    for (int col = 0; col < c_cols; col++) {
+    for (unsigned col = 0; col < c_cols; col++) {
         if (col == p->column) continue;
         consider(s, col, p->row);
     }
 
-    for (int row = 0; row < c_rows; row++) {
+    for (unsigned row = 0; row < c_rows; row++) {
         if (row == p->row) continue;
         consider(s, p->column, row);
     }
@@ -228,22 +228,22 @@ void knight_positions(struct search_status* s, struct piece_position* p) {
 void bishop_positions(struct search_status* s, struct piece_position* p) {
     unsigned cs = columns(s->chessboard);
     unsigned rs = rows(s->chessboard);
-    int r, c;
+    unsigned r, c;
 
-    for (r = p->row - 1, c = p->column - 1; r >= 0 && c >= 0; r--, c--) {
-        consider(s, c, r);
+    for (r = p->row, c = p->column; r >= 1 && c >= 1; r--, c--) {
+        consider(s, c - 1, r - 1);
     }
 
     for (r = p->row + 1, c = p->column + 1; r < rs && c < cs; r++, c++) {
         consider(s, c, r);
     }
 
-    for (r = p->row - 1, c = p->column + 1; r >= 0 && c < cs; r--, c++) {
-        consider(s, c, r);
+    for (r = p->row, c = p->column + 1; r >= 1 && c < cs; r--, c++) {
+        consider(s, c, r - 1);
     }
 
-    for (r = p->row + 1, c = p->column - 1; r < rs && c >= 0; r++, c--) {
-        consider(s, c, r);
+    for (r = p->row + 1, c = p->column; r < rs && c >= 1; r++, c--) {
+        consider(s, c - 1, r);
     }
 }