--- a/test/test-rules-helper.c	Tue Aug 25 18:59:18 2026 +0200
+++ b/test/test-rules-helper.c	Tue Aug 25 19:42:15 2026 +0200
@@ -44,7 +44,7 @@
     CX_TEST_DO {
         for (Rank r = 0 ; r < 8 ; r++) {
             for (File f = 0 ; f < 8 ; f++) {
-                CX_TEST_ASSERT(field_color(r, f) == colors[r][f]);
+                CX_TEST_ASSERT(field_color(f, r) == colors[r][f]);
             }
         }
     }