diff --git a/ab-openldap/ab-openldap-update.sh b/ab-openldap/ab-openldap-update.sh
index 4c357c1..1e46fe3 100755
--- a/ab-openldap/ab-openldap-update.sh
+++ b/ab-openldap/ab-openldap-update.sh
@@ -90,7 +90,7 @@ fi
 
 ### script self-update
 printf "checking for updates to this script... "
-localScriptChecksum=$( sha256 "./$scriptName" | grep -o '^\S*' )
+localScriptChecksum=$( sha256sum "./$scriptName" | grep -o '^\S*' )
 repoScriptChecksum=$( grep "$scriptName" "$checksumFilename" | grep -o '^\S*' )
 if [ "$localScriptChecksum" = "$repoScriptChecksum" ]; then
     printf "[NONE]\n"