diff --git a/tools/regression/bin/sh/builtins/locale1.0 b/tools/regression/bin/sh/builtins/locale1.0
index 93a37dfc876..90b10944c5a 100644
--- a/tools/regression/bin/sh/builtins/locale1.0
+++ b/tools/regression/bin/sh/builtins/locale1.0
@@ -11,6 +11,7 @@ check() {
 }
 
 unset LANG LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME LC_MESSAGES
+unset LANGUAGE
 
 msgeng="No such file or directory"
 msgdut="Bestand of map niet gevonden"
diff --git a/tools/regression/bin/sh/expansion/cmdsubst3.0 b/tools/regression/bin/sh/expansion/cmdsubst3.0
index dce972066e5..abb6b225a25 100644
--- a/tools/regression/bin/sh/expansion/cmdsubst3.0
+++ b/tools/regression/bin/sh/expansion/cmdsubst3.0
@@ -1,5 +1,8 @@
 # $FreeBSD$
 
+unset LC_ALL
+export LC_CTYPE=en_US.ISO8859-1
+
 e=
 for i in 0 1 2 3; do
 	for j in 0 1 2 3 4 5 6 7; do