diff --git a/x38ShLibClasses/src/com/ejie/x38/UdaFilter.java b/x38ShLibClasses/src/com/ejie/x38/UdaFilter.java
index 78085a5b..710d2f6e 100644
--- a/x38ShLibClasses/src/com/ejie/x38/UdaFilter.java
+++ b/x38ShLibClasses/src/com/ejie/x38/UdaFilter.java
@@ -66,6 +66,7 @@ public void doFilter(ServletRequest request, ServletResponse response, FilterCha
 					Pattern.CASE_INSENSITIVE).matcher(httpServletRequest.getHeader("referer")).find();
 		} else {
 			refersFromSecuritySystem = false;
+			logger.debug("Referer is null. If a value was expected, check if the protocol is still the same.");
 		}
 
 		try {