diff --git a/Dockerfile b/Dockerfile
index 0396c83..9be5cf5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -23,7 +23,7 @@ ENV \
     LDAP_BIND=yes \
     LDAP_VERSION=3 \
     LDAP_BASE="dc=example,dc=org" \
-    LDAP_SCOPE=sub \
+    LDAP_SCOPE=subtree \
     LDAP_USER_ATTRS="=home=/vmail/mail/%d/%n, =uid=5000, =gid=5000" \
     LDAP_USER_FILTER="(&(objectClass=inetOrgPerson)(uid=%n))" \
     LDAP_PASS_ATTRS="userPassword=password, =userdb_home=/vmail/mail/%d/%n, =userdb_uid=5000, =userdb_gid=5000" \