diff --git a/Makefile b/Makefile
index 7844064..d01e74d 100644
--- a/Makefile
+++ b/Makefile
@@ -236,6 +236,9 @@ COPYDIRS=
 # files for example.  You can generate data files.  Whatever you
 # might need.
 #
+# You should generate these files in the $(GENDIR) directory or
+# within a subdirectory under $(GENDIR) which you create yourself.
+#
 # All of your commands associated with a rule _must_ start with a tab
 # character.  Xcode makes it a bit tough to type a tab character by
 # default.  Press option-tab within Xcode to insert a tab character.