diff --git a/src/Expr.cc b/src/Expr.cc
index f6d1fc568e..5eadaad631 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -359,7 +359,7 @@ bool NameExpr::DoUnserialize(UnserialInfo* info)
 		if ( id )
 			::Ref(id);
 		else
-			reporter->Warning("unserialized unknown global name");
+			reporter->Warning("persistent state config changed: unserialized unknown global name");
 
 		delete [] name;
 		}