diff --git a/config.sub b/config.sub
index c16bede..07dd7f6 100755
--- a/config.sub
+++ b/config.sub
@@ -4,7 +4,7 @@
 
 # shellcheck disable=SC2006,SC2268 # see below for rationale
 
-timestamp='2021-07-06'
+timestamp='2021-08-04'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -1701,7 +1701,7 @@ fi
 # Now, validate our (potentially fixed-up) OS.
 case $os in
 	# Sometimes we do "kernel-libc", so those need to count as OSes.
-	musl* | newlib* | uclibc*)
+	musl* | newlib* | relibc* | uclibc*)
 		;;
 	# Likewise for "kernel-abi"
 	eabi* | gnueabi*)
@@ -1759,11 +1759,12 @@ esac
 # As a final step for OS-related things, validate the OS-kernel combination
 # (given a valid OS), if there is a kernel.
 case $kernel-$os in
-	linux-gnu* | linux-dietlibc* | linux-android* | linux-newlib* | linux-musl* | linux-uclibc* )
+	linux-gnu* | linux-dietlibc* | linux-android* | linux-newlib* \
+		   | linux-musl* | linux-relibc* | linux-uclibc* )
 		;;
 	uclinux-uclibc* )
 		;;
-	-dietlibc* | -newlib* | -musl* | -uclibc* )
+	-dietlibc* | -newlib* | -musl* | -relibc* | -uclibc* )
 		# These are just libc implementations, not actual OSes, and thus
 		# require a kernel.
 		echo "Invalid configuration \`$1': libc \`$os' needs explicit kernel." 1>&2
diff --git a/doc/config.sub.1 b/doc/config.sub.1
index d1b991a..7c5c8ae 100644
--- a/doc/config.sub.1
+++ b/doc/config.sub.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.47.16.
-.TH CONFIG.SUB "1" "July 2021" "GNU config.sub (2021-07-06)" "User Commands"
+.TH CONFIG.SUB "1" "August 2021" "GNU config.sub (2021-08-04)" "User Commands"
 .SH NAME
 config.sub \- validate and canonicalize a configuration triplet
 .SH SYNOPSIS
diff --git a/testsuite/config-sub.data b/testsuite/config-sub.data
index a592348..d58521b 100644
--- a/testsuite/config-sub.data
+++ b/testsuite/config-sub.data
@@ -841,6 +841,7 @@ x86_64-ericsson-dicos				x86_64-ericsson-dicos
 x86_64-fuchsia					x86_64-pc-fuchsia
 x86_64-genode					x86_64-pc-genode
 x86_64-glidix					x86_64-pc-glidix
+x86_64-linux-relibc				x86_64-pc-linux-relibc
 x86_64-nto					x86_64-pc-nto-qnx
 x86_64-os108					x86_64-pc-os108
 x86_64-pc-ptx					x86_64-pc-ptx