diff --git a/conf/vars.xml b/conf/vars.xml
index 392ef3eeb5..eecf4691c9 100644
--- a/conf/vars.xml
+++ b/conf/vars.xml
@@ -1,5 +1,6 @@
   <!-- Preprocessor Variables
        These are introduced when configuration strings must be consistent across modules. 
+       NOTICE: YOU CAN NOT COMMENT OUT AN X-PRE-PROCESS line, Remove the line instead.
    -->
   <X-PRE-PROCESS cmd="set" data="sound_prefix=$${base_dir}/sounds/en/us/callie"/>
   <!--