diff --git a/DDCore/include/ROOT/LinkDef.h b/DDCore/include/ROOT/LinkDef.h
index 81fb5cc5fdab2072663f0a1454bc112f080fcdd8..ebbf8f5b182c20b8dadf094f5147eda54a86f629 100644
--- a/DDCore/include/ROOT/LinkDef.h
+++ b/DDCore/include/ROOT/LinkDef.h
@@ -17,6 +17,15 @@
 //
 
 #ifdef __GNUC__
+
+//--------------------------------------------------------------------------
+//  These are the common warnings, which are generated by rootcling
+//  and which cannot be avoided at all. We hence disable them in the
+//  corresponding compilation units to reduce annoying warnings.
+//
+//  M.Frank
+//--------------------------------------------------------------------------
+
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 #pragma GCC diagnostic ignored "-Wdeprecated"
 #pragma GCC diagnostic ignored "-Wunused"