diff --git a/psGrammar/demos/demoErsti/commands.jsgf b/psGrammar/demos/demoErsti/commands.jsgf
index cda48d66e6f378dad433b469d105e70fbbd0f0f9..81b71a4c1c36a5bfd30dd77b81b61c04d16fe9ec 100644
--- a/psGrammar/demos/demoErsti/commands.jsgf
+++ b/psGrammar/demos/demoErsti/commands.jsgf
@@ -16,7 +16,7 @@ public <command> = [<robot>] ( <introduce> | <save> | <wait> | <goTo> | <followM
 
 <gravity> = (gravity compensation) | (show me your gripper) | (switch to gravity mode);
 
-<exit> = (end the (demonstration | demo))
+<exit> = (end the (demonstration | demo));
 
 <lookAt> = (look at camera one | look at the camera);