diff --git a/tests/01-basic-usage.php b/tests/01-basic-usage.php
index c7aa9d3..c22e9cd 100644
--- a/tests/01-basic-usage.php
+++ b/tests/01-basic-usage.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action(
 	'mb_relationships_init',
 	function () {
diff --git a/tests/02-categories-to-posts.php b/tests/02-categories-to-posts.php
index a7d4b60..b8ee744 100644
--- a/tests/02-categories-to-posts.php
+++ b/tests/02-categories-to-posts.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action(
 	'mb_relationships_init',
 	function () {
diff --git a/tests/03-users-to-posts.php b/tests/03-users-to-posts.php
index 38979d0..c26a482 100644
--- a/tests/03-users-to-posts.php
+++ b/tests/03-users-to-posts.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action(
 	'mb_relationships_init',
 	function () {
diff --git a/tests/04-each-connected.php b/tests/04-each-connected.php
index a8bc74f..c8bcecb 100644
--- a/tests/04-each-connected.php
+++ b/tests/04-each-connected.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action(
 	'mb_relationships_init',
 	function () {
diff --git a/tests/05-sibling-api.php b/tests/05-sibling-api.php
index 6677996..868be31 100644
--- a/tests/05-sibling-api.php
+++ b/tests/05-sibling-api.php
@@ -1,4 +1,7 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
 
 add_action(
 	'mb_relationships_init',
diff --git a/tests/06-exclude-from-search.php b/tests/06-exclude-from-search.php
index 80c0929..a5738be 100644
--- a/tests/06-exclude-from-search.php
+++ b/tests/06-exclude-from-search.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action(
 	'init',
 	function() {
diff --git a/tests/07-query-by-multiple-relationships.php b/tests/07-query-by-multiple-relationships.php
index 013db76..b635dc8 100644
--- a/tests/07-query-by-multiple-relationships.php
+++ b/tests/07-query-by-multiple-relationships.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 /**
  * This test creates 2 relationships: from posts to pages and from posts to posts.
  * Then it queries for connected items from the current post and belong to either the relationship.
diff --git a/tests/08-reciprocal.php b/tests/08-reciprocal.php
index 55e6a6b..b87d94c 100644
--- a/tests/08-reciprocal.php
+++ b/tests/08-reciprocal.php
@@ -1,4 +1,8 @@
 <?php
+if ( ! defined( 'ABSPATH' ) ) {
+	return;
+}
+
 add_action( 'mb_relationships_init', function () {
 	MB_Relationships_API::register( [
 		'id'         => 'posts_to_posts',