diff --git a/RAP4/customizations/bootstrap/files/ExecEngineFunctions.php b/RAP4/customizations/bootstrap/files/ExecEngineFunctions.php
index 138faaa5..31cd862b 100644
--- a/RAP4/customizations/bootstrap/files/ExecEngineFunctions.php
+++ b/RAP4/customizations/bootstrap/files/ExecEngineFunctions.php
@@ -320,7 +320,10 @@
          * - run kubectl apply -f "student-manifest-{{student}}.yaml"
         */
 
+        $pattern = '/[\W+]/';
+
         $studentName=strtolower($userName);
+        $studentName = preg_replace($pattern, '-', $studentName);
 
         $namespace=getenv('RAP_KUBERNETES_NAMESPACE');
         $containerImage=getenv('RAP_STUDENT_PROTO_IMAGE');