--- a/config_subdir.m4	2022-09-18 15:46:15.000000000 +0200
+++ b/config_subdir.m4	2026-10-19 17:14:27.511792097 +0200
@@ -7,6 +7,6 @@ AC_DEFUN([AX_CONFIG_SUBDIR_OPTION],
 AC_CONFIG_SUBDIRS([$1])
 
 m4_ifblank([$2], [rm -f $srcdir/$1/configure.gnu],
-[echo -e '#!/bin/sh\nexec "`dirname "'\$'0"`/configure" '"$2"' "'\$'@"' > "$srcdir/$1/configure.gnu"
+[printf '#!/bin/sh\nexec "`dirname "'\$'0"`/configure" %s "'\$'@"\n' "$2" > "$srcdir/$1/configure.gnu"
 ])
 ])