diff --git a/lam/lib/adminHeader.inc b/lam/lib/adminHeader.inc
index ff70fe2a..f053fd2a 100644
--- a/lam/lib/adminHeader.inc
+++ b/lam/lib/adminHeader.inc
@@ -40,7 +40,7 @@ elseif (is_file("../../../templates/login.php")) {
 }
 
 /** tool definitions */
-include_once($headerPrefix . "/lib/tools.inc");
+include_once(__DIR__ . "/tools.inc");
 
 $pro = '';
 if (isLAMProVersion()) {
diff --git a/lam/templates/main_header.php b/lam/templates/main_header.php
index 6bb2ea23..42fe8109 100644
--- a/lam/templates/main_header.php
+++ b/lam/templates/main_header.php
@@ -33,7 +33,7 @@ if (is_file("../login.php")) $headerPrefix = "../";
 elseif (is_file("../../login.php")) $headerPrefix = "../../";
 
 /** tool definitions */
-include_once($headerPrefix . "../lib/tools.inc");
+include_once(__DIR__ . "/../lib/tools.inc");
 
 $pro = '';
 if (isLAMProVersion()) {