diff -urNp -x '*.orig' busybox-1.31.1.org/shell/ash.c busybox-1.31.1/shell/ash.c
--- busybox-1.31.1.org/shell/ash.c	2019-10-21 16:54:40.000000000 +0200
+++ busybox-1.31.1/shell/ash.c	2021-10-21 10:29:26.053148921 +0200
@@ -2096,7 +2096,7 @@ static const struct {
 	{ VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL"      , changemail      },
 	{ VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH"  , changemail      },
 #endif
-	{ VSTRFIXED|VTEXTFIXED       , bb_PATH_root_path, changepath },
+	{ VSTRFIXED|VTEXTFIXED|VEXPORT, bb_PATH_root_path, changepath },
 	{ VSTRFIXED|VTEXTFIXED       , "PS1=$ "    , NULL            },
 	{ VSTRFIXED|VTEXTFIXED       , "PS2=> "    , NULL            },
 	{ VSTRFIXED|VTEXTFIXED       , "PS4=+ "    , NULL            },