diff --git a/LCS/Common/include/Common/HEADER.h b/LCS/Common/include/Common/HEADER.h
index 99fe79cb9f02b36569469ea45326dcb62485f781..941440a84566f528d8f717afe1ba17f0c6dd33c2 100644
--- a/LCS/Common/include/Common/HEADER.h
+++ b/LCS/Common/include/Common/HEADER.h
@@ -23,7 +23,7 @@
 #ifndef PACKAGE_FILENAME_H
 #define PACKAGE_FILENAME_H
 
-#include <lofar_config.h>
+//# Never #include <config.h> or #include <lofar_config.h> in a header file!
 
 //# Includes
 #include <otherpackage/file.h>
diff --git a/LCS/Common/src/HEADER.cc b/LCS/Common/src/HEADER.cc
index 90218f856ddca79dc17cea0bd57baadabdf8d19f..77052809b3e2f57fed0edbb98b309c5f0eb5e8d4 100644
--- a/LCS/Common/src/HEADER.cc
+++ b/LCS/Common/src/HEADER.cc
@@ -20,6 +20,11 @@
 //#
 //#  $Id$
 
+//# Always #include <lofar_config.h> first!
+#include <lofar_config.h>
+
+//# Includes
+
 namespace LOFAR
 {
 
diff --git a/LCS/Common/src/HEADER.h b/LCS/Common/src/HEADER.h
index 99fe79cb9f02b36569469ea45326dcb62485f781..941440a84566f528d8f717afe1ba17f0c6dd33c2 100644
--- a/LCS/Common/src/HEADER.h
+++ b/LCS/Common/src/HEADER.h
@@ -23,7 +23,7 @@
 #ifndef PACKAGE_FILENAME_H
 #define PACKAGE_FILENAME_H
 
-#include <lofar_config.h>
+//# Never #include <config.h> or #include <lofar_config.h> in a header file!
 
 //# Includes
 #include <otherpackage/file.h>