--- a/demo/Makefile.am
+++ b/demo/Makefile.am
@@ -20,7 +20,7 @@
 
 all: $(BINARY_FILES)
 
-$(BINARY_FILES): ../src/bf_test $(top_srcdir)/demo/dodecahedron.dat
+$(BINARY_FILES) &: ../src/bf_test $(top_srcdir)/demo/dodecahedron.dat
 	@echo Creating binary data files
 	test "$(top_srcdir)" = "$(top_builddir)" || cp $(top_srcdir)/demo/dodecahedron.dat .
 	@../src/bf_test