diff --git a/makefile-templates/Makefile.lecture b/makefile-templates/Makefile.lecture
index 15f4ee2..404d760 100755
--- a/makefile-templates/Makefile.lecture
+++ b/makefile-templates/Makefile.lecture
@@ -74,6 +74,7 @@
 ################################################################################
 #
 # Specify the current lecture chapter number. THIS MUST BE DEFINED!
+# Set it to whatever you like if you don't use it (see below).
 #
 CHAPTER?=$(error The required variable CHAPTER has not been defined. Please set it to the correct chapter number for this set of lectures)
 
@@ -99,6 +100,11 @@
 # being built. This is necessary if, for example, the current set of
 # lectures has no figures and examples.
 #
+# Alternatively, you can use to set the base name of the source and target
+# files if this is a one-off lecture that doesn't fall into the standard
+# chapter convention. (Set CHAPTER above to whatever you like if you don't
+# use it.)
+#
 # SLIDES=
 # FIGURES=
 # COMBINED=