diff --git a/jpeg/Makefile b/jpeg/Makefile
index f25541940ce2906c280c632ebc9cb4543a13a6de..6b3e61429ff3d3f170c86323973eb2cc8e0982c5 100644
--- a/jpeg/Makefile
+++ b/jpeg/Makefile
@@ -1,3 +1,7 @@
+#
+# WARNING: This file was modified for inclusion in Gmsh
+#
+
 # Generated automatically from Makefile.auto by configure.
 # Makefile for Independent JPEG Group's software