diff --git a/lib/dummy/Makefile b/lib/dummy/Makefile
index d3801078b..e5f1e9cab 100755
--- a/lib/dummy/Makefile
+++ b/lib/dummy/Makefile
@@ -1,3 +1,18 @@
+## Makefile for lib/dummy.
+#
+## Make a dummy libm library so that -lm works.
+#
+#
+#LIBRARIES=libm
+#
+#libm_OBJECTS=dummy.o
+#
+#include ../Makefile.inc
+#
+#dummy.c:
+#	echo "int __dummy__;" > $@
+#
+
 # Makefile for lib/dummy.
 
 # Make a dummy libm library so that -lm works.