diff --git a/Makefile b/Makefile
index a6aa2408c..f97f84bf1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,12 @@
-all: build/top.bit
+all: build/top.bit build/top.fpg
 
 build/top.bit build/top.bin:
 	./build.py
 
+build/top.fpg: build/top.bin
+	make -C tools
+	tools/byteswap $< $@
+
 load: build/top.bit
 	jtag -n load.jtag