diff -Naur libgd-gd-2.3.3/src/gd.h libgd-gd-2.3.3.new/src/gd.h
--- libgd-gd-2.3.3/src/gd.h	2021-09-11 07:09:44.000000000 +0200
+++ libgd-gd-2.3.3.new/src/gd.h	2024-05-15 10:05:41.193608534 +0200
@@ -1604,6 +1604,11 @@
 BGD_DECLARE(void) gdImageFlipVertical(gdImagePtr im);
 BGD_DECLARE(void) gdImageFlipBoth(gdImagePtr im);
 
+#define GD_FLIP_HORINZONTAL 1 /* typo, kept for BC */
+#define GD_FLIP_HORIZONTAL 1
+#define GD_FLIP_VERTICAL 2
+#define GD_FLIP_BOTH 3
+
 /**
  * Group: Crop
  *