diff --git a/index.php b/index.php
index 274d07a..db75619 100644
--- a/index.php
+++ b/index.php
@@ -70,19 +70,23 @@ if (isset($_SESSION[LookingGlass::SESSION_ERROR_MESSAGE])) {
 }
 
 if (LG_BLOCK_CUSTOM) {
-    include LG_CUSTOM_PHP;
+    if (defined('LG_CUSTOM_PHP') && file_exists(LG_CUSTOM_PHP)) {
+        include LG_CUSTOM_PHP;
+    }
 
-    ob_start();
-    include LG_CUSTOM_HTML;
-    $templateData['custom_html'] = ob_get_clean();
+    if (defined('LG_CUSTOM_HTML') && file_exists(LG_CUSTOM_HTML)) {
+        ob_start();
+        include LG_CUSTOM_HTML;
+        $templateData['custom_html'] = ob_get_clean();
+    }
 
-    if (defined('LG_CUSTOM_HEADER_PHP')) {
+    if (defined('LG_CUSTOM_HEADER_PHP') && file_exists(LG_CUSTOM_HEADER_PHP)) {
         ob_start();
         include LG_CUSTOM_HEADER_PHP;
         $templateData['custom_header'] = ob_get_clean();
     }
 
-    if (defined('LG_CUSTOM_FOOTER_PHP')) {
+    if (defined('LG_CUSTOM_FOOTER_PHP') && file_exists(LG_CUSTOM_FOOTER_PHP)) {
         ob_start();
         include LG_CUSTOM_FOOTER_PHP;
         $templateData['custom_footer'] = ob_get_clean();