diff --git a/src/DynareBison.yy b/src/DynareBison.yy
index 96ae5857307a4b33a7112add36f63f87e403fc2f..ad7ed5ec8bd6103b452a70d044fc32749b1b89f9 100644
--- a/src/DynareBison.yy
+++ b/src/DynareBison.yy
@@ -1,3 +1,4 @@
+// -*- C++ -*-
 /*
  * Copyright (C) 2003-2018 Dynare Team
  *
diff --git a/src/DynareFlex.ll b/src/DynareFlex.ll
index 1b6cbf7c48f209398af5c7755cf184e6c399569e..9d7248920cfebbc68be993cf7f92effb33467f8e 100644
--- a/src/DynareFlex.ll
+++ b/src/DynareFlex.ll
@@ -1,3 +1,4 @@
+/* -*- C++ -*- */
 /*
  * Copyright (C) 2003-2018 Dynare Team
  *
diff --git a/src/macro/MacroBison.yy b/src/macro/MacroBison.yy
index 07ff4daa509d32b92f9c10feb63d24207aa04c4f..4453fa7fff34d031cb3dc2f50d00257103d4815d 100644
--- a/src/macro/MacroBison.yy
+++ b/src/macro/MacroBison.yy
@@ -1,3 +1,4 @@
+// -*- C++ -*-
 /*
  * Copyright (C) 2008-2018 Dynare Team
  *
diff --git a/src/macro/MacroFlex.ll b/src/macro/MacroFlex.ll
index 2b3b34b483fe7be9400940242772dd0bf631271d..f88798f8494c39951703e1aa959226b14f060a51 100644
--- a/src/macro/MacroFlex.ll
+++ b/src/macro/MacroFlex.ll
@@ -1,3 +1,4 @@
+/* -*- C++ -*- */
 /*
  * Copyright (C) 2008-2018 Dynare Team
  *