diff --git a/share/cht.sh-posix.txt b/share/cht.sh-posix.txt
index 86afd70..e5614e3 100755
--- a/share/cht.sh-posix.txt
+++ b/share/cht.sh-posix.txt
@@ -35,7 +35,7 @@ case "$OSTYPE" in
 esac
 
 # for KSH93
-if ! local foo 2>/dev/null; then
+if echo $KSH_VERSION | grep -q ' 93' && ! local foo 2>/dev/null; then
   alias local=typeset
 fi