diff --git a/lam/lib/account.inc b/lam/lib/account.inc
index e0aa0ff6..d461b2ed 100644
--- a/lam/lib/account.inc
+++ b/lam/lib/account.inc
@@ -417,7 +417,7 @@ function get_preg($argument, $regexp) {
 					$pregexpr = '/^((([\\\][\\\])|(%))([a-zA-Z0-9%\\.-])+)([\\\]([[:alnum:]%\\.\\$\\ \\_-])+)+$/u';
 					break;
 		case "logonscript":	// path to login-script. normal unix file
-					$pregexpr = '/^(([\/])*([[:alnum:]%\\.\\ \\$\\_-])+([\/]([[:alnum:]%\\.\\ \\$\\_-])+)*((\\.bat)|(\\.cmd)|(\\.exe)))*$/u';
+					$pregexpr = '/^(([\/\\\])*([[:alnum:]%\\.\\ \\$\\_-])+([\/\\\]([[:alnum:]%\\.\\ \\$\\_-])+)*((\\.bat)|(\\.cmd)|(\\.exe)))*$/u';
 					break;
 		case "workstations":	// comma separated list with windows-hosts
 					$pregexpr = '/^(([a-zA-Z0-9\\.\\_-])+(,[a-zA-Z0-9\\.\\_-])*)*$/';