diff --git a/src/Basic_Requirement_Checker.php b/src/Basic_Requirement_Checker.php
index a1a5ca85c92c7a27288d4dcc0a4e013381538fd1..538599d71897ea39686e23ddfff8d98720bb2a12 100644
--- a/src/Basic_Requirement_Checker.php
+++ b/src/Basic_Requirement_Checker.php
@@ -1,6 +1,6 @@
 <?php
 
-if ( ! class_exists( 'WPDesk_Translable' ) ) {
+if ( ! interface_exists( 'WPDesk_Translable' ) ) {
 	require_once 'Translable.php';
 }
 
diff --git a/src/Plugin/Has_Plugin_Info.php b/src/Plugin/Has_Plugin_Info.php
index 6d3654457d6cccedc199acda6ce44c799a102905..18a0171603c912674664a1231fbcda5009d31fe5 100644
--- a/src/Plugin/Has_Plugin_Info.php
+++ b/src/Plugin/Has_Plugin_Info.php
@@ -1,6 +1,6 @@
 <?php
 
-if (!class_exists('WPDesk_Translable')) {
+if ( ! interface_exists( 'WPDesk_Translable' ) ) {
 	require_once dirname(__FILE__) . '/../Translable.php';
 }
 
diff --git a/src/Plugin/Plugin_Info.php b/src/Plugin/Plugin_Info.php
index 073ad496cacbf113068a15dddfed63bf26fbe39f..b74bf0bd6070f80d8190377d2a17e77ad59d1d3d 100644
--- a/src/Plugin/Plugin_Info.php
+++ b/src/Plugin/Plugin_Info.php
@@ -1,12 +1,12 @@
 <?php
 
-if (!class_exists('WPDesk_Translable')) {
+if ( ! interface_exists( 'WPDesk_Translable' ) ) {
 	require_once dirname(__FILE__) . '/../Translable.php';
 }
-if (!class_exists('WPDesk_Buildable')) {
+if ( ! class_exists( 'WPDesk_Buildable' ) ) {
 	require_once dirname(__FILE__) . '/../Buildable.php';
 }
-if (!class_exists('WPDesk_Has_Plugin_Info')) {
+if ( ! class_exists( 'WPDesk_Has_Plugin_Info' ) ) {
 	require_once 'Has_Plugin_Info.php';
 }