diff --git a/Makefile b/Makefile
index ad7e288e097..adaf03c3b96 100644
--- a/Makefile
+++ b/Makefile
@@ -323,6 +323,8 @@ DEMO_FILES = \
 	$(DIRECTORY)/progs/demos/*.cxx			\
 	$(DIRECTORY)/progs/demos/*.dat			\
 	$(DIRECTORY)/progs/demos/README			\
+	$(DIRECTORY)/progs/osdemos/Makefile		\
+	$(DIRECTORY)/progs/osdemos/*.c			\
 	$(DIRECTORY)/progs/xdemos/Makefile*		\
 	$(DIRECTORY)/progs/xdemos/descrip.mms		\
 	$(DIRECTORY)/progs/xdemos/*.[chf]		\