diff --git a/ChangeLog b/ChangeLog
index 0a526f8..a6663d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-13  Ben Elliston  <bje@gnu.org>
+
+	* config.guess: Disable SC2154 and SC2172 Shellcheck warnings.
+	* Makefile (shellcheck): Don't disable SC2172 globally.
+
 2018-07-13  John Ericson  <john.ericson@obsidian.systems>
 
 	* config.sub: Don't recognize every *-unknown as a basic_machine.
diff --git a/Makefile b/Makefile
index f90c418..9744deb 100644
--- a/Makefile
+++ b/Makefile
@@ -17,4 +17,4 @@ check-sub:
 	cd testsuite && sh config-sub.sh
 
 shellcheck:
-	shellcheck -e SC2006,SC2039,SC2172 -f gcc config.guess config.sub testsuite/*.sh
+	shellcheck -e SC2006,SC2039 -f gcc config.guess config.sub testsuite/*.sh
diff --git a/config.guess b/config.guess
index ad5d65e..ab55d4d 100755
--- a/config.guess
+++ b/config.guess
@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2018 Free Software Foundation, Inc.
 
-timestamp='2018-07-12'
+timestamp='2018-07-13'
 
 # 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
@@ -95,6 +95,7 @@ fi
 # Portable tmp directory creation inspired by the Autoconf team.
 
 tmp=
+# shellcheck disable=SC2172
 trap 'test -z "$tmp" || rm -fr "$tmp"' 1 2 13 15
 trap 'exitcode=$?; test -z "$tmp" || rm -fr "$tmp"; exit $exitcode' 0
 
@@ -1359,6 +1360,7 @@ EOF
 	# "uname -m" is not consistent, so use $cputype instead. 386
 	# is converted to i386 for consistency with other x86
 	# operating systems.
+	# shellcheck disable=SC2154
 	if test "$cputype" = 386; then
 	    UNAME_MACHINE=i386
 	else