diff --git a/Build.sh b/Build.sh
index ee24571..5380a56 100644
--- a/Build.sh
+++ b/Build.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# $MirOS: src/bin/mksh/Build.sh,v 1.275 2007/10/25 15:23:08 tg Exp $
+# $MirOS: src/bin/mksh/Build.sh,v 1.276 2008/02/29 11:48:31 tg Exp $
 #-
 # Environment used: CC CFLAGS CPPFLAGS LDFLAGS LIBS NOWARN NROFF TARGET_OS
 # CPPFLAGS recognised:	MKSH_SMALL MKSH_ASSUME_UTF8 MKSH_NOPWNAM MKSH_NOVI
@@ -18,6 +18,8 @@ if test -d /usr/xpg4/bin/. >/dev/null 2>&1; then
 	PATH=/usr/xpg4/bin:$PATH
 	export PATH
 fi
+tr=/usr/ucb/tr	# Solaris: /usr/xpg4/bin/tr fails the rot13 tr command
+test -f $tr || tr=tr
 
 if test -n "${ZSH_VERSION+x}" && (emulate sh) >/dev/null 2>&1; then
 	emulate sh
@@ -45,7 +47,7 @@ if test -t 1; then
 fi
 
 upper() {
-	echo :"$@" | sed 's/^://' | tr $alll $allu
+	echo :"$@" | sed 's/^://' | $tr $alll $allu
 }
 
 # clean up after ac_testrun()
@@ -174,7 +176,7 @@ ac_header() {
 		na=0
 	fi
 	hf=$1; shift
-	hv=`echo "$hf" | tr -d '\012\015' | tr -c $alll$allu$alln $alls`
+	hv=`echo "$hf" | $tr -d '\012\015' | $tr -c $alll$allu$alln $alls`
 	for i
 	do
 		echo "#include <$i>" >>x
@@ -382,7 +384,7 @@ cat >scn.c <<-'EOF'
 	#endif
 EOF
 ct=unknown
-eval 'v "$CPP scn.c | grep ct= | tr -d \\\\015 >x" 2>&'$h | sed 's/^/] /'
+eval 'v "$CPP scn.c | grep ct= | $tr -d \\\\015 >x" 2>&'$h | sed 's/^/] /'
 test 1 = $h && sed 's/^/[ /' x
 eval `cat x`
 rm -f x
@@ -483,7 +485,7 @@ NOWARN=$save_NOWARN
 #
 # Compiler: extra flags (-O2 -f* -W* etc.)
 #
-i=`echo :"$orig_CFLAGS" | sed 's/^://' | tr -c -d $alll$allu$alln`
+i=`echo :"$orig_CFLAGS" | sed 's/^://' | $tr -c -d $alll$allu$alln`
 # optimisation: only if orig_CFLAGS is empty
 test x"$i" = x"" && if test $ct = sunpro; then
 	cat >x <<-'EOF'
@@ -991,6 +993,7 @@ case $curdir in
 *\ *)	echo "#!./mksh" >test.sh ;;
 *)	echo "#!$curdir/mksh" >test.sh ;;
 esac
+echo "export tr=$tr" >>test.sh
 echo "export PATH='$PATH'" >>test.sh
 echo "exec perl '$srcdir/check.pl' -s '$srcdir/check.t'" \
     "-p '$curdir/mksh' -C $check_categories \$*$tsts" >>test.sh
diff --git a/check.t b/check.t
index 3be7f00..e0af903 100644
--- a/check.t
+++ b/check.t
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.149 2008/02/27 12:49:53 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.150 2008/02/29 11:48:32 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -1292,12 +1292,12 @@ description:
 stdin:
 	bar="bar
 		baz"
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<foo
-	$0 -c "tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<foo"
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<"$bar"
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<'$bar'
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<\$bar
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<-foo
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<foo
+	$0 -c "$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<foo"
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<"$bar"
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<'$bar'
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<\$bar
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<-foo
 expected-stdout:
 	sbb
 	sbb
@@ -1314,7 +1314,7 @@ stdin:
 	fnord=42
 	bar="bar
 		 \$fnord baz"
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<$bar
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<$bar
 expected-stdout:
 	one $sabeq onm
 category: bash
@@ -1326,7 +1326,7 @@ stdin:
 	fnord=42
 	bar="bar
 		 \$fnord baz"
-	tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<$bar
+	$tr '[A-Za-z]' '[N-ZA-Mn-za-m]' <<<$bar
 expected-stdout:
 	one
 		 $sabeq onm
diff --git a/dot.mkshrc b/dot.mkshrc
index 57a8407..81e70ae 100644
--- a/dot.mkshrc
+++ b/dot.mkshrc
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/dot.mkshrc,v 1.24 2007/10/25 14:54:00 tg Exp $
+# $MirOS: src/bin/mksh/dot.mkshrc,v 1.25 2008/02/29 11:48:32 tg Exp $
 #-
 # Copyright (c) 2007
 #	Thorsten Glaser <tg@mirbsd.de>
@@ -52,7 +52,11 @@ alias la='l -a'
 alias ll='l -l'
 alias lo='la -lo'
 alias which='whence -p'
-whence -p rot13 >&- || alias rot13='tr [A-Za-z] [N-ZA-Mn-za-m]'
+whence -p rot13 >&- || if [[ -x /usr/ucb/tr ]]; then
+	alias rot13="/usr/ucb/tr '[A-Za-z]' '[N-ZA-Mn-za-m]'"
+else
+	alias rot13="tr '[A-Za-z]' '[N-ZA-Mn-za-m]'"
+fi
 whence -p hd >&- || function hd {
 	hexdump -e '"%08.8_ax  " 8/1 "%02X " " - " 8/1 "%02X "' \
 	    -e '"  |" "%_p"' -e '"|\n"' "$@"