diff --git a/backend/TE/TakeExercise.php b/backend/TE/TakeExercise.php
index 46991afef27c9a0359e73a71f8ac4070418d5303..cc56b9ada3afef4ae5aa01d57c6a2eb4a5a89b05 100644
--- a/backend/TE/TakeExercise.php
+++ b/backend/TE/TakeExercise.php
@@ -120,7 +120,7 @@ class ExerciseFrame extends Node
                         'name' => $_SESSION[ 'user' ][ 'name' ], 
                         'username' => $_SESSION[ 'user' ][ 'username' ], 
                         'tutor' => $_SESSION[ 'user' ][ 'isadmin' ], 
-                        'switchedUser' => $_SESSION[ 'user' ][ 'switchedUser' ],
+                        'switchedUser' => isset( $_SESSION[ 'user' ][ 'switchedUser' ] ) ? $_SESSION[ 'user' ][ 'switchedUser' ] : "",
                         'email' => isset( $_SESSION[ 'user' ][ 'email' ] ) ? $_SESSION[ 'user' ][ 'email' ]: "" 
                 ), 
                 'mark' => array (
diff --git a/js/pianos4.js b/js/pianos4.js
index a86468145f08e849b90e8bfb330020075d40d4c7..c1171201a89bdcc17f350eaa512343cc006df2a6 100644
--- a/js/pianos4.js
+++ b/js/pianos4.js
@@ -2496,7 +2496,7 @@ function Pianos4( params )
                 } ) );
         }
         
-        if( ! params.user.tutor )
+        if( ! params.user.tutor && params.user.switchedUser )
         {
             buttons.push( createButton( 'switchback', 'Switch back to tutor', 'Go back as tutor' )
                 .css( 'margin-left', '30px' )