diff --git a/acf-FIELD_NAME-v4.php b/acf-FIELD_NAME-v4.php
index 4e85b52..b44e9b4 100644
--- a/acf-FIELD_NAME-v4.php
+++ b/acf-FIELD_NAME-v4.php
@@ -1,4 +1,6 @@
 <?php
+// Exit if accessed directly
+if ( !defined( 'ABSPATH' ) ) exit;
 
 class acf_field_FIELD_NAME extends acf_field {
 	
diff --git a/acf-FIELD_NAME-v5.php b/acf-FIELD_NAME-v5.php
index f230127..59ff47b 100644
--- a/acf-FIELD_NAME-v5.php
+++ b/acf-FIELD_NAME-v5.php
@@ -1,4 +1,6 @@
 <?php
+// Exit if accessed directly
+if ( !defined( 'ABSPATH' ) ) exit;
 
 class acf_field_FIELD_NAME extends acf_field {
 	
diff --git a/acf-FIELD_NAME.php b/acf-FIELD_NAME.php
index c540d9f..cfebc97 100644
--- a/acf-FIELD_NAME.php
+++ b/acf-FIELD_NAME.php
@@ -12,7 +12,8 @@
 */
 
 
-
+// Exit if accessed directly
+if ( !defined( 'ABSPATH' ) ) exit;
 
 // 1. set text domain
 // Reference: https://codex.wordpress.org/Function_Reference/load_plugin_textdomain