diff --git a/samples/erase/mondrian.xpm b/samples/erase/mondrian.xpm
index ad2e33a2b5..86d0ef8e8a 100644
--- a/samples/erase/mondrian.xpm
+++ b/samples/erase/mondrian.xpm
@@ -1,5 +1,5 @@
 /* XPM */
-static char *mondrian_xpm[] = {
+static const char *mondrian_xpm[] = {
 /* columns rows colors chars-per-pixel */
 "32 32 7 1",
 "  c Black",